Military Historical Library

In March- April 1950 the command of the South Korean army began to move new units to the 38^th Parallel and strengthen the forces that they had placed there. The divisions and regiments were manned to full tabular strength by means of a new draft. Heavy weapons were taken from units within the depths of the country and moved closer to the 38^th Parallel. The units and formations began to increase their combat training. The manning and training of the forces was examined by a commission from the South Korean Headquarters and their American advisors.

In the first half of May 1950 General Roberts, in assessing the status of the South Korean army, said that it was manned, armed and trained per American regulations and was a completely modern army, able to carry out war with any army that was twice or even three times its numerical size, under conditions of identical technical equipping.

At the end of May – beginning of June the command of the South Korean army began to increase the preparations of the army for possible conflict with the DPRK. Divisional and corps headquarters moved to practical deployment of their forces per the plans for possible scenarios of operations. By mid June the South Korean forces were concentrated in their initial areas and brought to full combat readiness.

Just before the start of the armed conflict Secretary of Defense Johnson, head of the Joint Chiefs of Staff General Bradley, and State Department advisor Dulles made a special trip to

Japan

where they met with General McArthur on the question of the possible onset of military operations. Immediately after this meeting Dulles went to South Korea , where he became familiar with the status of the South Korean armed forces located on the 38^th Parallel. Appearing before the “National Assembly” of South Korea on 19 June 1950, Dulles approved of the preparation of the forces for military operations and asserted that the USA was prepared to provide the necessary moral and material support to

South Korea

in its struggle against the North Koreans.

The American military were sure that the South Koreans were able to crush the Korean Peoples’ Army without any special difficulty and to occupy the DPRK. Therefore the Singman Rhee regime was assured that with the start of a military conflict they would receive support, but only in the form of American aviation and naval power. If necessary, the American divisions located in Japan would be rapidly sent to the aid of the South Korean army.

By the summer of 1950 out of eight infantry divisions (with a total of 21 infantry regiments), one independent infantry regiment, two independent infantry battalions, three independent artillery battalions, and one aviation detachment that composed the South Korean army, five divisions with 15 infantry regiments were located along the 38^th Parallel (more than 70% of the overall number of infantry regiments) as well as one independent cavalry regiment, one independent battalion, the three independent artillery battalions, and all of the aviation assets. The most powerful of the force groupings was located on the Pyongyang direction north of Seoul . It follows to stress that the most well trained divisions were concentrated along the 38^th Parallel, fully manned with personnel and all materiel components.

In the Soviet historiography it stresses that the command of the South Korean army and their American advisors, in considering all of the tasks to be carried out in case of offensive combat operations, paid insufficient attention to the organization of the defense. Defense was only organized over a short depth and without consideration of the tactical qualities of the terrain. In the main it was planned around a number of strong points and nodes of resistance, covering the main roads and mountain valleys. Only along the Seoul direction (the sectors of Kaysen and Sinuipin) was there a system of developed defensive works and barriers. On this direction the depth of the defense extended for 20 kilometers.

In May 1950 the government of the DPRK, in preparing for conflict, also carried out training of its forces in combat operations. First and foremost they took measures to strengthen the defensive line immediately behind the 38^th Parallel and in the depths of the territory, especially along the Pyongyang direction. In addition to their six infantry divisions they began forming four more infantry divisions (the 4^th, 10^th, 13^th and 15^th.)

Along the 38^th Parallel, as well as the two border brigades and two divisions already there (the 1^st and 3^rd) they concentrated another seven infantry divisions (the 2^nd, 4^th, 5^th, 6^th, 12^th, 13^th and 15^th), the 105^th Tank Brigade, and the 603^rd Motorcycle Regiment. The main body of the force grouping was deployed in the Kimchong-Unchong sector to cover the Pyongyang direction. Here the forces were deployed in two echelons with consideration given to creating a reasonably deep defense. The 10^th Infantry Division was located in the Pyongyang area.

The 3^rd Border Brigade was operating along the western coast, reinforced by one infantry regiment, an artillery battalion and a self-propelled artillery battalion from the 6^th Infantry Division.

There were six infantry divisions deployed along the Pyongyang direction (the 1^st, 3^rd, 4^th, 6^th, 13^th and 15^th) as well as the 105^th Tank Brigade and 17^th Independent Artillery Regiment, with the 1^st, 3^rd, 4^th and 6^th in the first echelon and the 13^th and 15^th in the second echelon. The main body of the 105^th Tank Brigade (less the 203^rd Tank Regiment) was located in the second echelon as well; the 203^rd Tank Regiment had its battalions allocated to the 1^st, 4^thand 6^th Infantry Divisions with the goal of reinforcing their defense. The 17^th Independent Artillery Regiment was allocated out by battalions to the 3^rd, 4^th and 6^th Infantry Divisions.

The 1^st Border Brigade was deployed along the eastern coast along with the 10^th Infantry Regiment, an artillery battalion and a battery of self-propelled guns from the 5^th Infantry Division, and the main body of the 5^th Infantry Division formed the second echelon in the Koson area.

As a result, thanks to the timely regrouping of the KPA from the depths of the country to the 38^th Parallel, the force relationships were as follows (See Table 1).

Type of Unit

KPA Forces (1^st, 3^rd, 4^th, 6^th, 2^nd, and 12^th ID, 105^th TBr, 17^th IndAR

South Korean forces (1^st, 7^th, 6^th, 8^th, and Capital ID, IndCavRegt, two IndInfBn, three IndArtyBn

Force Ratio*

Across the Entire Front

Battalions

Guns and Mortars

Tanks and SP Guns

Aircraft¹

Ships

787

185

699

1.3 : 1

1.1 : 1

5.9 : 1

1.2 : 1

1 : 2.2

On the Ongdin and Yenan Peninsulas

Battalions

Guns and Mortars

Tanks and SP Guns

1 : 1.3

1 : 2

On the Pyongyang Direction

Battalions

Guns and Mortars

Tanks and SP Guns

436

173

432

1.4 : 1

1 : 1

5.5 : 1

On the Huachen and Koson Directions

Battalions

Guns and Mortars

Tanks and SP Guns

324

210

1 : 1

1.5 : 1

¹Overall the KPA had 172 combat aircraft but only 32 trained pilots.

For that reason, the numerical and qualitative superiority of the KPA forces concentrated on the 38^th Parallel and especially on the Seoul direction gave them advantageous preconditions for succeeding in carrying out the missions levied on the KPA during the course of a possible armed conflict.

Soviet sources indicate that on 19 June 1950 the chief of the General Staff of the South Korean army gave an order to convert their forces over to the offensive. But at the same time, they were not able to go over to the offensive, as the headquarters of the 1^st Corps had not set up any command and control for the use of artillery. A commission from the headquarters of the South Korean army was quickly sent to the headquarters 1^st Corps along with a large group of American advisors. After examining the reasons for the breakdown in the offensive and making the necessary changes the offensive was designated to start on 25 June 1950. And starting on 23 June the South Korean forces opened up a sustained artillery bombardment of KPA positions, so that by dawn on 25 June, with artillery and aviation support, they could go over to the offensive along the entire length of the front along the 38^th Parallel and in some places had invaded the territory of the Democratic Peoples Republic of Korea to a depth of 1-2 kilometers. The forces of the KPA put up a strong resistance to the South Korean forces and drove back their offensive. It was only along the Chorwon and Kimchong directions and north of the Ongdin that South Korean forces succeed in advancing to a depth of 1-2 kilometers north of the 38^th Parallel.

American sources claim that at 0400 hours on Sunday, 25 June 1950, the North Korean forces began their military campaign with the political goal of reuniting North and South Korea under Communist power. The military goals of the campaign were to seize and establish supremacy over South Korea . The publication of a host of materials in contemporary Russia indirectly support that claim.

But at the same time all sides from the very beginning support the fact that the KPA began its offensive on 25 June 1950. The concept for this offensive consisted of the points that, by launching the main strike from the areas of Kimchong, Yongchong, Chorwon in the general direction of Seoul, Suwon and a secondary strike from Huachen, Inde, and Yangu to enter Seoul from the southeast in the direction of Suwon would break enemy resistance, encircle and destroy his main forces in the Seoul area, and moved towards the line Suwon – Wonchu – Samchok.

The 6^th, 1^st, 4^th and 3^rd Infantry Divisions with the 105^th Tank Brigade had to be on the main axis of advance towards Seoul .

The 2^nd and 12^th Infantry Divisions and the 603^rd Motorcycle Regiment received the mission to launch the strike towards Yangu, Suwon and cut off the line of retreat for the main body of the South Korean forces to leave Seoul towards the south and southeast.

The 1^st Border Brigade with the 10^th Infantry Regiment from the 5^th Infantry Division had to advance in the direction of Kannin to joint up with a naval landing (two battalions of marines and two student battalions) which it had been proposed to land in the Kannin area with the mission of seizing Kannin to prevent the enemy from withdrawing to the south, as well as prevent him from moving reserves north to the front lines.

The 3 ^rd Border Brigade with the regiment from the 6 ^th Infantry Division, deploying to the right of the main force grouping, had to liberate the Ongdin and Yenan peninsulas. [3]

The ultimate goal was to destroy the enemy’s reserves and developing the offensive on these directions: Suwon , Chyongnan, Nonsan, Kuanju, Mokpo ; Ochonin, Chongju, Taejon , Namwon, Resu; Wonju, Andong, Pusan – which would virtually liberate all of South Korea .

After a 30 minute artillery preparatory fire, the forces of the Korean Peoples Army went over to the counteroffensive.

On the Seoul direction, as the result of good organization and conduct of the system of artillery preparatory fires, the enemy was suppressed, and the units of the 1^st, 4^th and 3^rd KPA Infantry Divisions along with the 105^th KPA Tank Brigade were able to penetrate 6-8 kilometers to the south of the 38^th Parallel even in the first few hours of the offensive, and the units of the 6^th KPA Infantry Division had been able to seize Kaysen after the first two hours of the counteroffensive.

The command of the South Korean forces strove to bring order to demoralized units that were operating in the first echelon, and began to swiftly bring up the second echelon and the reserves. The enemy was able to succeed in taking up tactically advantageous points and lines along the direction of advance and put up a stiff resistance before the KPA forces. In specific, the enemy used counterattacks and fires to stop the advance of the 1^st KPA Infantry Division after only 6-8 kilometers south of the 38^th Parallel by the end of 25 June.

After crushing enemy forces in Kaysen, the 6^th KPA Infantry Division began to pursue the 12^th Infantry Regiment of the 1^st ROK Infantry Division, and by the end of the day on 25 June had moved to the Han River in the sectors of Yonchonni and Baykoku.

The 3 ^rd and 4 ^th KPA Infantry Divisions, who were fighting with the second echelon, overwhelmed enemy resistance and by the end of the day were fighting in Donduchen and Sinuipin.

For that reason, as a whole the offensive on the Seoul direction on the first day had developed successfully. The greatest success on this day was achieved by the 6 ^th, 4 ^th and 3 ^rd KPA Infantry Divisions, who had covered 8-12 kilometers, penetrated the enemy’s defenses and driven in the flanks of the enemy’s force grouping operating on the Seoul direction.

On the Ongdin peninsula, units of the 3^rd KPA Border Brigade, reinforced by the 1^st KPA Infantry Regiment, an artillery battalion and a battery of self-propelled artillery guns from the 6^th KPA Infantry Division, successfully attacked the enemy and by the end of the day on 25 June had eliminated organized resistance. During the course of the battles they had captured nearly 2,000 enemy soldiers and officers and all of the combat technology of the 17^th ROK Regiment of the ROK Capital Infantry Division. During the night of 26 June the remnants of the 17^th ROK Regiment, numbering 400 men in all, used boats and rafts to cross to Teyonphyondo Island (whose garrison was evacuated on 29 June to Kunsan). By 1030 hours on 26 June the Ongdin peninsula was totally cleared of enemy forces. By this time units of the 3^rd KPA Border Brigade had obliterated the 1^st Battalion, 12^th ROK Regiment, 1^st ROK Infantry Division, and seized the Yenan peninsula as well.

The offensive in the eastern sector of the front developed with less success. Units of the 2^nd and 12^th KPA Infantry Divisions and the 1^st KPA Border Brigade, operating under difficult terrain conditions and encountering strong enemy resistance, only managed to penetrate to a depth of 2-5 kilometers. By the evening of 25 June a naval landing had taken place on the coast in the area of Kannin and Samchok.

The units of the 6^th KPA Infantry Division, who on the previous evening had advanced to the Han River , prepared to make a forced crossing of this serious water obstacle. The width of the river in places was up to six kilometers, and its depth was five meters. Due to a lack of crossing equipment and some disorganization only three battalions with two 76mm regimental guns had been moved to the left bank of the river. These subunits seized a bridgehead of up to 3 kilometers deep. By morning on 27 June, and in spite of strengthening resistance by the enemy, the main body of the 13^th and 15^th KPA Regiments, two batteries of an artillery regiment, and a battery of the 2^nd Battalion 17^th Independent KPA Artillery Regiment had been moved across the river. The remaining forces of the division crossed on the night of 28 June.

After a short artillery preparation at dawn on 27 June, the 13 ^th and 15 ^th KPA Infantry Regiments attacked the enemy and widened the bridgehead to 5-6 kilometers. By the end of the day units of the division had crossed the Siomari-Suitanri line. Further advances were halted by fire and counterattacks by the 12 ^th Regiment 1 ^st ROK Division and 22 ^nd Regiment 3 ^rd ROK Division, sent up from Taegu , two student battalions from the Seoul Infantry Academy , and other enemy subunits moved out of Seoul .

The 1^st KPA Infantry Division, brought up from the second echelon, once again renewed the offensive on the morning of 26 June. But at the same time the enemy had brought up the 11^th Regiment 1^st ROK Infantry Division during the night. The battle dragged on ceaselessly during the day and no one gained success. It was only by evening that the units of the 1^st KPA Infantry Division silenced enemy resistance and began to move forward. By 1600 hours on 27 June they had taken Munsan, but having not organized a method to prevent the enemy from moving, gave them the opportunity to again reinforce the heights 7 kilometers southeast of Munsan, and therefore their attempts to continue their offensive on that day were not successful.

Units of the 4^th KPA Infantry Division, which went on the offensive on the morning of 26 June, were able to destroy the 1^st Regiment 7^th ROK Infantry Division in the Dokchonni area thanks to skillful and decisive operations, and then continue to develop the offensive in the direction of Uidenpu.

The 3 ^rd KPA Infantry Division, together with units of the 105 ^th Tank Brigade, took Sinipni and, after destroying subunits of the 3 ^rd Regiment 7 ^th ROK Infantry Division and the 5 ^th Regiment of the 2 ^nd ROK Infantry Division that had been rushed into that area, likewise advanced on Uidenpu. At 1700 hours on 26 June units of the 4 ^th and 3 ^rd KPA Infantry Divisions, along with the 105 ^th Tank Brigade attached the enemy in Uidenpu and after a hour and a half battle took the city.

At 0900 hours on 27 June the 4 ^th and 3 ^rd KPA Infantry Divisions and the 105 ^th Tank Brigade renewed the offensive. Withdrawing units of the 7 ^th ROK Infantry Division and the 5 ^th Regiment 2 ^nd ROK Infantry Division put up resisting fires, blew up bridges, roads, and planted mines in individual sectors. By 2100 hours the advancing units had moved to a line 4-7 kilometers northwest, north and northeast of Seoul .

After a two-day battle the 2^nd KPA Infantry Division took Chunchen on the evening of 27 June and by the end of the day was moving towards Kaphyon. At this time one battalion of the 6^th Regiment, advancing through the mountains, took Kaphyon and cut a railway bridge 2 kilometers north of the city that led into Seoul . The 12^th KPA Infantry Division, slowly moving forward, by the end of the day on 27 June had occupied a line 14 kilometers northeast of Honchen. The 1^st Border Brigade at this time was fighting a battle for the city of Kannin .

As a result of this three day offensive KPA forces had inflicted heavy losses on the main body of enemy forces concentrated along the 38^th Parallel. The greatest success for the KPA was on the Seoul direction, having moved up to 50 kilometers and taking up the immediate approaches to Seoul itself.

The enemy, striving to halt the movement of the advancing KPA forces, had quickly brought up his reserves into the Seoul area. Even on 26/27 June elements of the 22^nd Regiment 3^rd ROK Infantry Division were engaged in combat in the Siomari and Konsonri areas, and the 5^th Regiment 2^nd ROK Infantry Division in the area south of Sinuipu. Later other units of the 2^nd ROK Infantry Division, as well as the 5^th ROK Infantry Division, were sent directly into Seoul .

The entrance of UN armed forces into the war. The destruction of the main body of South Korean forces and the threat to completely and rapidly crush the Singman Rhee regime called for a rapid reaction by the USA at the UN. At an emergency session of the Security Council of the UN (the USSR was boycotting this session, so the opportunity to use its veto was even more sorely missed) there was a call for an immediate cessation of hostilities and a withdrawal of DPRK forces.

Immediately after this US President Truman gave an order for US air and naval forces to provide cover and support to South Korean forces. At the same time Truman ordered the US 7^th Fleet “to prevent a strike against Formosa” and made plans to speed up military assistance to the Philippine government, which was fighting against its own people, and French forces who were leading the war against the Democratic Republic of Vietnam. For that reason, the US government, in breaking up the armed conflict in Korea , was simultaneously taking direct unfriendly actions against the Peoples Republic of China , by occupying the island of Taiwan ( Formosa ) and increasing their interference in internal affairs of the Philippines and going down a path which would widen combat operations against the Vietnamese people.

In his book “McArthur and His Meeting with History”[4] American General Whiting observed that American aviation commenced combat operations in South Korea on order from McArthur even before that order was given by his superior Truman, and from 27 June onward these operations took on a character of massive strikes not only against the KPA but on objects north of the 38^th Parallel as well. On that day the US Navy conducted naval bombardment of Korean coastal villages.

On the evening of 27 June, e.g. when the American armed forces had already begun their war with the DPRK, an incomplete meeting of the Security Council of the UN was held, which was illegal, but the members present approved a resolution backing the use of American forces in Korea .

On 7 July, per a request from the American representative, an extraordinary meeting of the Security Council was held in which all of the members of the UN who supported the resolution of 27 June, voted to provide armed forces and other assistance under the auspices of a unified command for the war against the DPRK. Simultaneously the Security Council asked the USA to take command of these forces and decide on their while flying the independent flag of the UN during the course of operations against the forces of North Korea simultaneously with the flags of the participating nations.

The American government designated the Supreme Commander of American Armed Forces in the Far East , General McArthur, to be the commander of UN forces.

With the introduction of American armed forces into the war, the situation for the DPRK worsened sharply. To support combat operations by their ground forces, the American command allocated the 19 ^th Strategic Aviation Group (19 ^th Bomb Group) to be moved from its bases on Guam to the island of Okinawa, the US 5 ^th Air Force which was located in Japan, two aircraft carrier groups (the 5 ^th US and 13 ^th British) based around the USS Valley Forge and HMS Triumph, and No. 77 Squadron RAAF which was based at Iwakuni (Japan). Out of the tasked formations and units now operating against the DPRK in early July 1950 there were 740 aircraft (30 heavy and 90 medium bombers, 430 fighters, 90 reconnaissance aircraft, and 100 transports). Beside that, starting on 13 July the 22 ^nd and 92 ^nd Heavy Bombardment Groups (65 aircraft) from the 15 ^th Air Force (strategic aviation) also took part in combat operations.

American aviation, striving first of all to destroy KPA aviation, launched raids on the airfield at Pyongyang , with the result that 19 aircraft were destroyed. Simultaneously American aviation launched strikes against industrial objects in the DPRK and moved to destroy the main railway nodes and lines of communication. The systematic bombardment also included the combat order, headquarters and rear services of the advancing KPA forces.

The KPA aviation, which was significantly inferior in numbers to that of the Americans, even in the first days of the war suffered heavy losses in both men and combat material (by 3 July they had lost 36 combat aircraft) and were not able to put up any resistance to superior enemy forces, and were therefore forced to only carry out reconnaissance missions on behalf of the ground forces.

The ships of the US Navy located in Korean territorial waters began a systematic bombardment of the coastal areas beginning on 27 June.

On 28 June the governments of England , Australia and New Zealand pledged their readiness to support the American command with their naval forces that were located in the Pacific Ocean . From that point onward there were 19 American ships operating in Korean waters (a heavy aircraft carrier, a heavy cruiser, a light cruiser, 12 destroyers, and 4 submarines) and 23 English and Australian ships (two light aircraft carriers, three light cruisers, eight destroyers, and 10 support vessels.)

The tiny navy of the DPRK, which consisted of few warships and which had already lost three torpedo boats and two sub chasers, could not put up reasonable resistance. Superiority at sea was thus yielded to the enemy.

But at the same time the ground forces of South Korea continued to withdraw from the blows of the KPA forces. The American command, upon seeing that the South Korean forces, in spite of the complete superiority of American air and naval power, suffered one defeat after another and could carry out any of the missions laid before them, began to move units of the 24^th US Infantry Division from Japan to Korea beginning on 1 July. One battalion of this division was brought into Taechon by transport aviation into on 2 July, but the rest of the division followed by sea. During the first period of the armed conflict, when only individual subunits of the American ground forces arrived in Korea , command and control over them was placed in the immediate hands of the chief of the military advisory group, who subordinated them to a field headquarters created on 27 June in Korea . On 2 July the command of American ground forces in Korea was turned over to the commander of the 24^th US Infantry Division, Major General Dean.

The command of the KPA, by studying the possibility that this war could drag on and that they lacked reserves, moved to form the 8^th and 9^th KPA Infantry Divisions on 1 July (based on the 1^st and 3^rd Border Brigades), two infantry brigades, two marine brigades, two tank brigades, two independent tank regiments, seven reserve regiments, two tank destroyer battalions, and five independent antiaircraft artillery battalions. Somewhat later on they began to form the 7^th KPA Infantry Division from the 7^th Border Brigade.

The size of the newly formed divisions was reduced in comparison with the tables of organization of the previous formed divisions. The new tables showed reduced numbers of rifles and carbines but a slight increase in the number of artillery and mortar weaponry. An antiaircraft artillery battalion was added to the tables of organization of the division.

The infantry brigades were formed from three infantry battalions, an artillery regiment, an antitank battalion, a self-propelled artillery battalion, a 120mm mortar battalion, an automatic rifle battalion, a signals battalion, a sapper-engineer battalion, and a medical battalion.

The normal tabular size and armaments of the newly formed infantry divisions and brigades is shown in Table 2.

Formation	Infantry Division	Infantry Brigade
Personnel	9,689	6,067
Rifles and carbines	6,547	3,315
Automatic rifles	1,932	772
Light machine guns	345	162
Heavy machine guns	202	60
Heavy caliber machine guns (antiaircraft)	36	24
Antitank rifles	129	72
37mm AA guns	12	-
45mm Antitank Guns	52	18
76mm and 122mm weapons	48	36
82mm and 120mm mortars	105	51
SU-76 SP artillery weapons	16	12
Cargo trucks	285	156
Special duty trucks	37	26

Personnel in the newly formed formations and units, as well as replacements for operational forces, were acquired primarily by asking for volunteers and only then by conscription by local governmental agencies.

It was significantly more difficult to man the newly formed units, as well as replace losses in the operational forces, with officer personnel since the KPA had possessed no officer reserves at the beginning of the war. Together with this all leadership positions in the army called for being filled by Party members and government workers. The best cadres previously had been those who were former partisan detachment commanders. Measures were taken to increase the network of military training establishments to train junior officers, but the training period for students in the military academies was reduced from one year to two months. Courses were created to improve formation commanders and broaden the courses for improving officers via the 1^st Central Academy .

3. Destruction of Enemy Force Groupings in the Seoul Area and Withdrawal to the Hangan-Kannin Line (28 June – 2 July.)

In spite of the heavy effects of American aviation on KPA forces, on 28 June the offensive continued. At dawn on 28 June units of the 6^th KPA Infantry Division attacked the enemy along the Siomari-Suitanri line, driving them back to the Kimpo area and after a ten-hour battle took the city. In order to prevent the further advance of the 6^th KPA Infantry Division, the enemy moved the 18^th ROK Infantry Regiment of the Capital Infantry Division into the area of Kimpo. During 29 June the 6^th KPA Infantry Division, after repulsing several enemy counterattacks which were supported by artillery and aviation strikes, fought a terrible battle for Kimpo airfield. Starting on the morning of 30 June the division again attacked the enemy, and overcoming stiff resistance, moved forward 6-8 kilometers and cut the Inchon-Seoul road. During 1 and 2 July units of the division fought along the line they had achieved, repulsing enemy counterattacks and persevering even under heavy enemy air attacks.

The 1^st KPA Infantry Division, in stiff combat that continued for all of 28 June, destroyed the enemy in the Konsonri area. Remnants of enemy forces hastily withdrew to the south. After seizing Konsonri the 1^st KPA Infantry Division was assigned to the second echelon.

The 4^th and 3^rd KPA Infantry Divisions and the 105^th Tank Brigade, who had advanced to the outskirts of Seoul by the end of 27 June, encountered enemy resistance in prepared defensive positions. During the night the infantry took up positions on the heights overlooking the city. At 0430 hours on 28 June the 3^rd KPA Infantry Division and the 105^th Tank Brigade attacked the enemy. An hour later the 4^th KPA Infantry Division also went back on the offensive. By 0530 hours on 28 June the forward detachment of the 105^th Tank Brigade had broken in Seoul , and by 0600 hours the main body of the brigade had seized the radio station, the electrical power plant, the post office, the telegraph and other administrative establishments of the city. Units of the 4^th KPA Infantry Division, who broke into the city virtually at the same time as the 105^th Tank Brigade, had taken the northern and central parts of the city by 1600 hours; the 3^rd KPA Infantry Division, coming into Seoul from the south, by that time had taken the southern part of the city. The enemy, abandoning his combat technology and equipment, hastily withdrew to the southern bank of the Han River .

Consequently the commanders of the units and formations of the KPA that had reached the Seoul area but did not immediately organize for a crossing of the Han River and did nothing to prevent the enemy from withdrawing permitted them to blow up the bridge over the river, and after bringing up units of the 2^nd and 5^th ROK Infantry Divisions, strengthened their defenses on the south bank of the river.

In order to reinforce their force grouping in the Seoul area, the KPA command transferred the 13 ^th KPA Infantry Division to that area.

By this time a Stavka of the High Command had been created in the area of Sopho (12 kilometers north of Pyongyang .)

The great distance of the General Staff from the forces (120 to 300 kilometers) and their inability to immediately control all of their formations made it necessary to create two operational groups with their headquarters deployed in Yongchon and Yangu. The 1 ^st KPA Operational Group had control of the 1 ^st, 3 ^rd, 4 ^th, 13 ^th and 15 ^th KPA Infantry Divisions, and the 2 ^nd KPA Operational Group had control of the 2 ^nd and 12 ^th Infantry Divisions and the 603 ^rd Motorcycle Regiment. The 5 ^th, 6 ^th and 10 ^th KPA Infantry Divisions and the 105 ^th Tank Division [5] remained immediately subordinate to the High Command. With a goal of closer leadership over the forces, an auxiliary command post of the General Staff was established in Chorwon. [6]

After a 15 minute artillery barrage at dawn on 29 June, the forward detachment of the 105 ^th Tank Division, consisting of a battalion from the motorcycle regiment, a company of tanks and a battery of SP guns, forced a crossing of the Han River and seized a bridgehead of up to 2 kilometers in frontage and 1 kilometer in depth. But at the same time the crossing of the forces and the dispersion of their force on the bridgehead left them with insufficient crossing means, and coupled with the continuous operations by American aviation meant that the rest of the forces were slow to cross. The main bodies of the 3 ^rd and 4 ^th KPA Infantry Divisions and the 105 ^th Tank Division had no success in crossing for three days. An insignificant amount of artillery had crossed with the leading subunits, and what had crossed had no prime movers or enough ammunition. The battle for the bridgehead took on a violent, protracted nature. The main body of the 3 ^rd KPA Infantry Division only managed to get completely across the Han River by the morning of 2 July, the 4 ^th KPA Infantry Division was completely across by the morning of 3 July, and the 105 ^th Tank Division on 4 July. The 105 ^th Tank Division for the most part had to cross via a bridge that was built by KPA sapper-engineers on 3 July with the help of local residents.

The 2^nd KPA Infantry Division, operating in difficult terrain and with insufficient skill in the use of its own artillery, slowly moved forward, overcoming stiff enemy resistance. By 30 June the division had reached the Han River , and after forcing a crossing, seized Kwanju on 2 July. The 12^th KPA Infantry Division advanced in the general direction of Oronri, Hongchen and Hensen, and on 2 July seized Wonju. In conjunction with that the offensive of the 2^nd and 12^th KPA Infantry Divisions had been slow from the very beginning, but when there was a breach between the flanks of the two divisions, the KPA command sent the 15^th KPA Infantry Division into that breach and on 30 June they engaged in combat in the Hongchen area along with the forces of the 603^rd Motorcycle Regiment’s motorcycle battalion along the direction of Inholi. By 2 July the division had moved to the Han River in the Inhoni and Hinhonli sectors and moved to force a crossing of the river.

On the east coast, the 1^st Border Brigade with the 10^th Regiment from the 5^th KPA Infantry Division had seized Kannin by 28 June and joined up with the naval landing which came ashore on 25 June, as well as partisans operating in the enemy’s rear area. After seizing Kannin the 1^st Border Brigade received a mission to defend the coast in the Kannin area and south. The 5^th KPA Infantry Division assembled in the Kannin area during 29-30 June, and on the morning of 1 July began to advance and on 2 July seized Samchong.

For that reason, as a result of combat operations from 25 June to 2 July the KPA forces, advancing with an average speed of 10 kilometers per day, had moved 75-80 kilometers and liberated a significant amount of the territory of South Korea including the capital city – Seoul. Forcing the Han River , they created conditions to develop a further offensive to the south.

During the course of combat operations the South Korean forces concentrated on the Seoul direction had suffered heavy losses and in point of fact were shattered. But at the same time the KPA troops were unable to surround and crush the enemy’s Seoul force grouping as had been planned.

The reasons for this were that the advancing forces operating on the Seoul direction had developed the offensive more slowly than had been planned. The 2 ^nd and 12 ^th KPA Infantry Divisions, along with the 603 ^rd Motorcycle Regiment, who were supposed to take Seoul from the southeast and cut off the retreat of the Seoul force grouping to the south and southeast, found their division commanders could not maintain tight control over their units and subunits, and the lack of artillery with the advancing forces and the difficult terrain conditions meant they could not carry out their missions. At the same time the units of the 3 ^rd and 4 ^th KPA Infantry Divisions and the 105 ^th Tank Division, who took Seoul, failed to immediately organize a forced crossing of the Han River, which permitted the enemy to withdraw his forces in good order, organize a defense on the south bank of the river, and later move his forces to the south.

American aviation was a major factor in the slow tempo of the KPA forces’ offensive, launching continuous attacks upon their troops, headquarters, and lines of communication starting on 27 June.

The Ministry of National Defense also had an extremely limited effect upon the successful development of the offensive due to its underestimation of troop command and control. Taking immediate command of all subordinate divisions, command and control was sorely tested. The creation of the 1 ^st and 2 ^nd Operational Groups using officers from this Ministry’s headquarters proved that they could not just be knocked together and they did not have sufficient communications assets. At the same time the commanders in a number of units and formations did not strive to ensure uninterrupted communications with higher chiefs or their neighbors, did not have firm control over their subordinate forces and failed to pay sufficient attention to reconnaissance.

There was no consciousness of the fact that if the KPA forces had succeeded in surrounding and destroying the Seoul force grouping of the South Korean army, then further events, undoubtedly, would have developed much more favorably for

North Korea

4. Development of the Offensive and Entry of the Forces of the Korean Peoples Army to the Line Poson – Kimsan – Yendong – Yonju – Yondok (3-25 July 1950)

By 3 July the KPA forces on the main direction had secured a bridgehead on the left bank of the Han River , ensuring for conditions to further develop the offensive. The most powerful force grouping was concentrated in the Seoul area on the Suwon direction (the 6^th, 4^th, 3^rd, and 2^nd KPA Infantry Divisions and the 105^th Tank Division.) The 15^th and 12^th KPA Infantry Divisions and 603^rd Motorcycle Regiment were operating along the central direction, and the 5^th KPA Infantry Division was on the east coast. The High Command had the 13^th KPA Infantry Division (in Seoul ), the 1^st KPA Infantry Division (west of Yonchonni) and the 10^th KPA Infantry Division (in Pyongyang ) in reserve.

The main force grouping of the South Korean forces was likewise located north of Suwon . Here they had the 18 ^th ROK Infantry Regiment from the Capital Division, the remnants of the 1 ^st and 7 ^th ROK Infantry Divisions, the 5 ^th and 2 ^nd ROK Infantry Divisions, and the 22 ^nd Regiment of the 3 ^rd ROK Infantry Division. Facing the 15 ^th and 12 ^th KPA Infantry Divisions were units of the 6 ^th ROK Infantry Division and the 2 ^nd ROK Infantry Regiment of the enemy’s Capital Division. The 8 ^th ROK Infantry Division had the bulk of its forces from the Kannin area withdraw to the southwest, but part of its units remained in the Samchok area. To reinforce those forces that were operating in Samchok, they hastily sent in the 23 ^rd Regiment of the 3 ^rd ROK Infantry Division and the 1 ^st Independent ROK Infantry Battalion.

The destruction inflicted upon the South Korean forces was sharply reflected in their combat capability and morale level. These were the conditions presented to the American command that led them to send their own forces into combat after moving them in from

Japan

Having created these conditions, the KPA command decided to renew the offensive on the morning of 3 July.

The goal of this offensive was conclude the destruction of the South Koreans and successfully prevent the arrival of American forces in Korea, a well as rapidly seize the ports along the southeastern coast at Pusan, Ul’san, and Pohang. Seizing these ports would limit the ability of the UN forces to send in new formations and material assets.

In order to rapidly achieve its stated goals, the KPA command decided to concentrate its main effort along the central direction, e.g. along those strips of terrain that formed limits by a conditional line to the west through Suwon – Taejon – Pusan and along the east from Wonju – Andong – Pohang.

The Suwon-Nonsan-Kwangju direction had the best terrain conditions, but at the same time it would not permit rapid accomplishment of tasks as it was too far from the ports of Pusan , Ul’san and Pohang . The shortest route to the ports was via Kannin, Samchok, and Pohang , but this could not permit sufficient volume of traffic to pass, was too far from the main force grouping of the KPA forces, and was too vulnerable to both naval and air interdiction.

At 0500 hours on 3 July, after a preparatory artillery bombardment against enemy troops and fire support assets units of the 6 ^th KPA Infantry Division struck to the southeast and units of the 4 ^th KPA Infantry Division drove west to simultaneously strike the enemy in Yendinpo, and by 0930 hours they had seized the city. The remnants of enemy forces, defending in Yendinpo, took heavy losses and part of their forces pulled back to Inchon and part of them pulled back to Suwon . After liberating Yendinpo the 13 ^th Regiment of the 6 ^th KPA Infantry Division with the 203 ^rd Tank Regiment of the 105 ^th Tank Division began to develop the offensive towards Inchon and by 0740 hours on 4 July had taken the port city.

Simultaneously with the beginning of the battles for Yendinpo the 3 ^rd and 2 ^nd KPA Infantry Divisions, along with the 105 ^th Tank Division, also attacked the opposing enemy forces, forcing them from their occupied line and began to pursue them.

After suffering destruction in the battles for Yendinpo and on the left bank of the Han River to the south and southeast of Seoul , the remnants of the Seoul force grouping began to hastily withdraw. At that time the lead elements of the 21 ^st Infantry Regiment of the 24 ^th US Infantry Division, flown in from Japan , were moving towards Usan. The main body of this regiment was assembling in Chyonan.

On 4 July units of the 105 ^th Tank Division and the 4 ^th KPA Infantry Division took Suwon , destroyed a battalion of the 24 ^th US Infantry Division in the area of Usan, and on 6 July took Pyongtaek. The 2 ^nd KPA Infantry Division at this time took Ansong.

The enemy, who was attempting to set up a line at Chyonan – Chinchong, prepared both cities for all-around defense, and destroyed and mined the roads leading into these cities from the north. They carried out particularly heavy destruction and mining of the sector of road from Pyongtaek to Chyonan. American aviation increased its activity, continually striking the KPA forces advancing along that direction.

With a goal of rapidly destroying the enemy in Chyonan the 105^th Tank Division, along with a battalion of artillery and a self-propelled artillery battalion from the 4^th KPA Infantry Division, moved down back roads towards Chyonan from the northwest. Simultaneously the 4^th KPA Infantry Division moved along the destroyed roads towards the city from the north. At 0400 hours on 8 July both divisions simultaneously attacked the enemy in Chyonan, and in a terrible battle destroyed the 21^st US Infantry Regiment and the remnants of two South Korean infantry regiments, and on 9 July the city was completely taken.

The 2 ^nd KPA Infantry Division, after overcoming enemy resistance, fought a battle on 8 July for Chinchon. During the course of the terrible three-day battle the division destroyed up to two South Korean infantry regiments and on 10 July took the city.

On the central and eastern directions the KPA forces, advancing under difficult conditions in mountainous terrain, slowly moved forward. The 15 ^th KPA Infantry Division, after forcing the Han River , took Chongju on 4 July, and Mugikli on 8 July. The 12 ^th KPA Infantry Division took Chungju with one regiment on 6 July, and on 9 July the main body seized Tanyan. The 5 ^th KPA Infantry Division, developing the offensive along the east coast, destroyed the enemy in the Samchok area with the cooperation of the partisans, and on 8 July took Uljin and moved to the south of this city. On 9 July, the enemy used naval bombardment to support the naval landing of two battalions of infantry in the rear of the 5 ^th KPA Infantry Division, with the concept in mind to operate in conjunction with forces attacking at the front in order to destroy the units of the 5 ^th KPA Infantry Division. But this concept was folly. Subunits of the 5 ^th KPA Infantry Division were rapidly rushed to the point of the landings, and as a result of their skillful and decisive actions the enemy landing was surrounded and crushed by 11 July.

For that reason, and in spite of complete air superiority, the enemy suffered destruction and was forced to pull back to the south. As a result of the blows inflicted by the KPA forces the South Korean forces were demoralized and command and control was lost. In the first clashes with KPA formations the lead elements of the 24 ^th US Infantry Division had taken serious losses. In conjunction with that the American command moved the 25 ^th US Infantry Division into Korea from Japan by sea during 8-14 July. Simultaneously they prepared to move the 1 ^st US Cavalry Division in from Japan as well.

On 12 July the lead elements of the US 8 ^th Army headquarters arrived in Korea, headed by Lieutenant General Walker, who had accepted command of all US forces in South Korea. Taking the harshest measures, the Americans to some level succeeded in restoring order in the South Korean forces. With a goal of creating a reserve the American command reorganized the 5 ^th ROK Infantry Division in Kwangju and the 7 ^th ROK Infantry Division in Namwon. They began to form the 10 ^th ROK Infantry Division in Pusan , and on Sanjuchado Island , a ROK marine division. They hastily replaced personnel and armaments in the divisions operating at the front.

After meeting only failure in their attempts to hold the line of Chyonan – Chinchon – Chunju, the American command took measures to halt the offensive by the KPA forces at the line of the Kim River – Poyin – Yongu – Pyoyenye. With this goal in mind they deployed the main body of the 24^th US Infantry Division along the Kim River in the area of Konju, and on the Poyin – Yenchon – Yenju line the main body of the newly arrived 25^th US Infantry Division, which sent out forward detachments.

The KPA command, with the goal of disrupting these efforts and destroying the enemy forces along those lines, decided to send the 3 ^rd and 6 ^th KPA Infantry Divisions into combat on the Taejon direction, and the 1 ^st KPA Infantry Division into the area of Chunju to operate between the 15 ^th and 12 ^th KPA Infantry Divisions. The 603 ^rd Motorcycle Regiment was taken out of the Wonju area, reorganized in the Chyonan area, and prepared to operate with the 6 ^th KPA Infantry Division.

In the interests of improving command and control and getting the leadership closer to the forces, on 13 July a front command and control was established based on the auxiliary command post of the General Staff, and two group armies (armies) were formed from the two operational groups – the 1 ^st KPA Group Army with the 2 ^nd, 3 ^rd, 4 ^th, and 6 ^th KPA Infantry Divisions and the 105 ^th Tank Division and 603 ^rd Motorcycle Regiment, and the 2 ^nd KPA Group Army with the 1 ^st, 5 ^th, 12 ^th, and 15 ^th KPA Infantry Divisions. The 13 ^th KPA Infantry Division became the Front Reserve, and the 10 ^th KPA Infantry Division the reserve of the High Command. [7]

On 11 July the 6 ^th KPA Infantry Division began its offensive with the 13 ^th KPA Infantry Regiment along the coast road, and on 14 June the main body, along with the 603 ^rd Motorcycle Regiment, moved forward along the direction of Onchonni-Kangye. They met with success and, crushing police units, likewise threw the enemy out of the ports of Mokpo and Resu which were held by marine battalions, and by 25 July had cleansed the enemy from the entire southwestern part of Korea . During the offensive they had again crushed the 5 ^th ROK Infantry Division, which had reformed in the Kwanju area and was sent into combat on the 22 ^nd in the Chonyp area.

The 4^th KPA Infantry Division, reinforced with a tank battalion from the 105^th Tank Division, after taking Chyonan deployed to advance to the south and on 10 July had moved to the approaches to Konju, where they met stiff resistance from the units of the 24^th US Infantry Division. During the period 11-13 July units of the 4^th KPA Infantry Division fought a terrible battle on the approaches to Konju and it was only on 14 July that they managed to crush the enemy on the north bank of the Kim River . After a short preparatory bombardment, at 1730 hours on 14 July they forced the river in the areas west and north of Konju and by 2200 hours had seized the city. In the battle for the city they wiped out more than 400 enemy soldiers and officers, captured 15 artillery weapons, 8 antiaircraft machine guns, 40 trucks, 20 radio sets and other equipment. After taking Konju the division received a mission to use its main body to pursue the enemy in the direction of Kimsan, but one regiment with the tank battalion would strike Taejon from the northwest, joining up with the 3^rd KPA Infantry Division and the 105^th Tank Division to destroy the enemy in this region.

The 105^th Tank Division and the 3^rd KPA Infantry Division fought a terrible battle between 9-11 July on the approaches to Chochiwon and it was 12 July before they could take the city. All of the roads leading out of Chochiwon to the south were destroyed by the enemy and mined. A strong point had been established in the area of Fukoni. Together with this the decision was made to cover the front with part of the forces and use the main body of the 105^th Tank Division and 3^rd KPA Infantry Division to come around Fukoni from the west. By 1100 hours on 13 Jukly the main bodies of these divisions had reached the Kim River in the area of Tyepenni, but at the same time attempts to force the river from the march were turned back by heavy enemy fire from the opposing bank. During 14 July units of both divisions conducted reconnaissance of the enemy and crossing points, brought up their artillery and at 2000 hours on 14 July began to force the river under artillery fire. Isolated subunits of the 3^rd KPA Infantry Division and the motorcycle regiment of the 105^th Tank Division succeeded in establishing a bridgehead on the opposing bank. During 15 and 16 July the infantry and artillery of both divisions crossed the river, but the tanks were unable to cross as the bridge in this area had not been repaired. Seeing this, the decision was made to have the 107^th and 109^th Tank Regiments of the 105^th Tank Division cross the Kim River in the area of Konju, e.g. within the defensive belt of the 4^th KPA Infantry Division, and this was completed by the morning of 17 July.

Crossing to the south bank of the Kim River, the 3 ^rd KPA Infantry Division and 105 ^th Tank Division together with the 4 ^th KPA Infantry Division launched a strike to the south on 17 July, then swinging to the east – into the rear area of the 24 ^th US Infantry Division, which was defending on the south bank of the Kim River south of Fukoni. Seeing the real threat of encirclement, the units of the 24 ^th US Infantry Division, which were in close combat with the KPA forces, hastily pulled back to Taejon with heavy losses.

During 19 July the 3 ^rd KPA Infantry Division and 105 ^th Tank Division brought themselves to order, carried out reconnaissance, and prepared to attack the enemy in Taejon . At 0430 hours on 20 July units of the 4 ^th KPA Infantry Division in the west, the 3 ^rd KPA Infantry Division in the northwest, and the 105 ^th Tank Division in the northeast and north all began to advance on Taejon . By 0600 hours the lead tank subunits had broken into the city, and by 1100 hours the main body had followed. The enemy suffered heavy losses in street battles and by the end of the day on 20 July had been forced out of the city.

During the course of the battles for Taejon and in the city itself the KPA forces had destroyed over 1200 enemy soldiers and officers, 40 trucks, 4 weapons, and 3 tanks and captured 60 guns and mortars, 7 tanks, 196 trucks, 16 radio sets and many other items of military goods. 108 enemy soldiers and officers had been taken prisoner, including the commander of the 34 ^th US Infantry Regiment. Later on the division commander of the 24 ^th US Infantry Division was also captured, General Dean. The remnants of the 24 ^th US Infantry Division hastily withdrew to the southeast. Soon this division was withdrawn to Taegu for reorganization.

In developing the offensive to the southeast, the units of the 4^th KPA Infantry Division took Kimsan on 25 July, but the 3^rd KPA Infantry Division and 105^th Tank Division had to force the Kim River for a second time, crushing the forward elements of the newly deployed 1^st US Cavalry Division and taking Yendon.

The 2 ^nd KPA Infantry Division, operating indecisively and with insufficient organization, slowly moved forward and by 22 July had taken Poyin.

At the same time the forces of the 2 ^nd KPA Group Army, moving against heavy enemy resistance and crossing difficult mountainous terrain conditions via roads and paths, slowly moved forward. By 25 July the 15 ^th, 1 ^st and 12 ^th KPA Infantry Divisions had moved to the Tahenri-Dokuni line, north of Yenchon and Yonju, where they engaged the main body of the 25 ^th US Infantry Division. Enemy resistance was strongly reinforced. The main body of the enemy was concentrated on holding important villages and road junctions.

On 13 July the 5 ^th KPA Infantry Division took Pyoyenye, and on the 20 ^th, Yongdok. Enemy forces, including units of the 3 ^rd ROK Infantry Division, as well as elements of the 1 ^st US Cavalry Division from Pohang , counterattacked the units of the 5 ^th KPA Infantry Division and forced it out of the city. On the night of 23 July, the division launched a surprise night attack that once again forced the enemy out of the city, and then fortified it.

For that reason, over the course of the month the greater part of South Korea had been liberated, with KPA forces moving nearly 400 kilometers on their right flank and 160-200 kilometers along their center. Between 3-25 July KPA forces had averaged from 3.5 – 7 kilometers per day and the 6 ^th KPA Infantry Division and the 603 ^rd Motorcycle Regiment had moved up to 12 kilometers per day. During the course of the battles the main body of the South Korean army had been crushed, and heavy losses inflicted on the 24 ^th US Infantry Division.

The American command, striving to provide assistance to the ground forces, constantly increased the activity of their aviation, which operated not only with the forces, but carried out a systematic bombing of cities and villages throughout Korea, burning and destroying schools, hospitals, etc. The US Navy blockaded the coasts of Korea and carried out a systematic shore bombardment of coastal villages.

Due to the constant operations of enemy aviation KPA forces, after the first half of the month, were forced to change over nearly exclusively to night operations.

A great deal of help was provided to the advancing forces of the Korean Peoples Army by partisan detachments operating in the enemy’s rear area. They destroyed railway bridges and roads, the withdrawal routes for the Singman Rhee forces, knocked out transportation means, launched strikes against withdrawing units and enemy troop echelons, and attacked the Singman Rhee police and shot down enemy troops and technology.

5. Offensive of the Korean Peoples Army on the Pusan Direction 26 July – 20 August 1950)

The American command sent the 24^th and 25^th US Infantry Divisions to Korea at the beginning of July. But at the same time these forces were insufficient to halt the offensive operations of the KPA forces.

The American divisions, after suffering losses, were also forced to withdraw. The British paper “Daily Mail and Morning Post” wrote: “While hoping that the participation of American ground forces would break the morale of the North Koreans and shatter their offensive spirit, such is not the case.”

In mid July the American command band to move additional forces to Japan including the 1 ^st US Cavalry Division and two independent infantry regiments. At the same time the US moved to hastily begin transfer of the 1 ^st US Infantry Division, the 1 ^st Marine Air Wing (starting on 14 July), and the 2 ^nd US Infantry Division (starting on 18 July) from the USA.

The American command attempted to create reserves in consideration of the South Korean forces and with this goal withdrew and reorganized two divisions. But at the same time this attempt did not bring success. Both of these divisions were soon thrown into combat once again.

Seeing that the South Koreans and American forces at this time were equipped with antitank means (60mm Bazooka and 57mm recoilless rifle) which were ineffective against KPA tanks, the Americans immediately placed the 88.9mm Bazooka into production and by the end of July had sent the first production lot of these arms to Korea by aircraft. At the end of July-beginning of August they also began to ship a large number of antitank mines to Korea .

By 26 July, this was the status of the enemy force grouping. The remnants of the 5 ^th ROK Infantry Division were operating in the area of Sunchon, and units of the 7 ^th ROK Infantry Division were in the Kimsan area. The hastily transferred 1 ^st US Cavalry Division was in the Yendon area. The remnants of the 24 ^th US Infantry Division that had been operating there moved to the Taegu area to reform. In the Pohin area and east were the 2 ^nd and 1 ^st ROK Infantry Divisions, and the 35 ^th Infantry Regiment of the 25 ^th US Infantry Division. Along the Yongu-east of Yenchong-Yenju line was the 6 ^th ROK Infantry Division, the Capital Division, and the 8 ^th ROK Infantry Division, and the 27 ^th and 24 ^th Infantry Regiments of the 25 ^th US Infantry Division. In the area south of Yondok was the 3 ^rd ROK Infantry Division along with the 1 ^st ROK Marine Battalion.

From this laydown it can be seen that the American command was taking every possible measure to strengthen the forces on the Taegu-Pusan direction from the northwest and the west. Here, along the line south of Kimsan to south of Yonju were concentrated two American and five South Korean divisions. The flanks of this force grouping were weak.

In accordance with the previously made decisions, the main force grouping of the KPA was also concentrated along the central direction along the line Kimsan-Yonju where seven of the nine divisions were operating on the front line. The forces which had been operating along the flanks had enjoyed considerable success: the 6 ^th KPA Infantry Division along with the 603 ^rd Motorcycle Regiment had reached the area of Mokpo and was on the approaches to Sunchon, having liberated all of the southwestern portion of Korea, and the 5 ^th KPA Infantry Division, taking Yondok, was only 40 kilometers from the port of Pohan. But at the same time the development of further success along these directions was not possible due to a lack of sufficient forces and means.

For that reason, the KPA was still far from achieving its ultimate goal in the operation. The forces of the main force grouping were 100-150 kilometers from the ports of Pusan , Ul’san and Pohan. The numbers of UN forces between them and their goal was growing every day, enemy resistance had stiffened, and conditions for the offensive in relation to enemy air activity had become more difficult. It was necessary to take all necessary measures to strengthen the speed of the advance of the main body of the force grouping of KPA troops.

Assessing the difficulty of the situation, the High Command of the KPA made the decision to first of all concentrate its main effort on the central direction, continue to advance, launch a strike with the forces of the 1 ^st KPA Group Army from the area of Yendon in the direction of Kimchon-Taegu and use the forces of the 2 ^nd KPA Group Army to strike from the area of Yechon-Yonju in the direction of Andon and Yonchon. This would require all available forces and means, for which the 2 ^nd KPA Group Army would be reinforced by the 8 ^th and 13 ^th KPA Infantry Divisions.

The 4 ^th KPA Infantry Division received the mission to advance from the Kimsan area in the direction of Chinan-Hyopchon-Kolchuldon. The 3 ^rd KPA Infantry Division, together with the 105 ^th Tank Division and the 2 ^nd KPA Infantry Division, was ordered to move in the direction of Kimchon. The 15 ^th and 1 ^st KPA Infantry Divisions had the task of advancing in the direction of Sanju. After taking these points the 15 ^th KPA Infantry Division had to advance in the direction of Kimchon, but the 1 ^st KPA Infantry Division in the direction of Chonsan-Taegu. The 12 ^th KPA Infantry Division had the mission of launching a strike against Andon with the subsequent development of success in the direction of Yison-Yonchon.

The 6 ^th KPA Infantry Division, along with the 603 ^rd Motorcycle Regiment, was ordered to use part of its forces to defend the port of Mokpo and the southern coast of Korea, and the main body of its forces to advance in the direction of Namwon, north of Sunchon and in the direction of Chinju. To defend the coastal area in the sectors of Kunsan, Mokpo , and Sunchon the 7 ^th KPA Infantry Division, which began forming on 20 July, would be sent there. Beside that, to strengthen the defenses on the southern and western coasts several previously created independent infantry regiments would be sent there, as well as two battalions of marines and two police battalions.

The 5^th KPA Infantry Division would temporarily (until they received ammunition resupply) have to go on the defense.

The 10 ^th KPA Infantry Division, located in the reserve of the High Command, was to be transferred from Pyongyang to the area of Taejon . The newly formed 9 ^th KPA Infantry Division and 16 ^th Tank Brigade would be moved to the area of Seoul . In the Pyongyang area, the newly formed 17 ^th Tank Brigade would be used to form the 17 ^th Mechanized Division.

Analysis of the decisions made by the KPA command showed that they were correct. In creating the situation where every day lost improved the position of the enemy, the only real means to achieve established goals was to speed up the offensive of the main force grouping and send in raw forces on those directions. The reorganization of the forces in the belts of the 6 ^th or 5 ^th KPA Infantry Divisions, where they had achieved the greatest territorial gains, would bring about a loss of time, and beside that, it was extremely difficult due to the conditions of the terrain and strong enemy air opposition.

To successfully carry out the decision taken, exclusively important significance was given to the speedy movement of units and formations of the KPA focused on reducing the enemy defenses, deep penetrations into his combat order and rapid movement into the southeastern coast. But at the same time, as subsequent combat showed, it was not possible to achieve these goals.

In carrying out the decision of the High Command, the forces of the Korean Peoples Army went on the offensive again starting on 26 July, moving on the eastern and southeastern directions.

The forces of the 1 ^st KPA Group Army had moved to the right bank of the Naktong River by the end of the day on 4 August in areas to the east of Hyopchon- Kimchon, where they fought a battle for crossing the river. At that time the 6 ^th KPA Infantry Division and 603 ^rd Motorcycle Regiment, advancing on the right flank of the 1 ^st KPA Group Army, took Chinju , forced the Ham River and fought a battle for Haman. After taking Kimchon the 2 ^nd KPA Infantry Division became the reserve of the 1 ^st KPA Group Army and by 6 August had assembled in the area southeast of Yendon. By 6 August the 10 ^th KPA Infantry Division had moved and assembled in the area of Koryo, where it became a subordinate formation of the 1 ^st KPA Group Army.

The American command, studying the serious threat by the Korean Peoples Army to break through their defenses along the southern coast and head to Pusan , began to hastily move raw troops from the line Masan-Channae-Hyonphun. Beginning on 31 July they transferred units of the 2 ^nd US Infantry Division (less the 38 ^th Infantry Regiment) to the Channae sector as soon as they debarked from ships, along with the 1 ^st US Marine Division. The 25 ^th US Infantry Division regrouped in the area of Masan , and the 29 ^th and 5 ^th independent US Infantry Regiments were also sent there. The operations of American forces in these areas was supported by naval gunfire from the Chinhae area as well as aviation.

By 7 August the 4^th KPA Infantry Division had managed to inflict damage on the units of the 1^st US Marine Division, and forcing the Naktong River , fought for Channae. The enemy brought up more and more new forces, including parts of those units of the 24^th US Infantry Division that they had replaced, and under the support of a large number of aircraft began to counterattack the 4^th KPA Infantry Division. The 4^th KPA Infantry Division took heavy losses and by the end of the day on 20 August was forced to withdraw to the left bank of the river.

By 8 August the 3 ^rd KPA Infantry Division and 105 ^th Tank Division had likewise forced the Naktong River , seizing a small bridgehead in the area of Uikwan. Units of the 1 ^st US Cavalry Division attempted a number of counterattacks in moves designed to force the crossing forces from their bridgehead. But at the same time none of these attempts met with success.

On 13 August the 10 ^th KPA Infantry Division entered into combat. It forced the Naktong River in the area north of Hyonphun, but it could not secure a bridgehead for itself and under heavy enemy pressure was forced to withdraw to the left bank of the river. On this date the enemy made a naval landing in the area of Sachon, striving to get into the rear area of the 6 ^th KPA Infantry Division. In order to break up this landing in the Chinju area, the main body of the 7 ^th KPA Infantry Division was brought up. The landing was wiped out.

Starting on 26 July, the 2 ^nd KPA Group Army likewise continued the offensive. On 29 June the 13 ^th KPA Infantry Division entered into combat on the direction of Sanju and the 8 ^th KPA Infantry Division on the direction of Yenchon. Overcoming the resistance of the 1 ^st, 6 ^th, and 8 ^th ROK Infantry Divisions and the Capital Division, the forces of the 2 ^nd KPA Group Army took the cities of Sanju, Yongu, and Andon, and between 2-4 August moved to the Naktong River . The 12 ^th KPA Infantry Division and units of the 8 ^th KPA Infantry Division forced the river and seized a bridgehead on its southern bank.

Over the next two days the main body of the 2 ^nd KPA Group Army forced the Naktong River and, overcoming stiff enemy resistance, moved to the southeast. By 20 August the 15 ^th, 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions had moved to the line Indon-Hwasudon. Here they encountered organized enemy resistance and were forced to terminate the advance.

At that time the 5 ^th KPA Infantry Division, under heavy enemy air attack and naval bombardment, overcoming resistance from the 3 ^rd ROK Infantry Division, slowly moved along the coastal roads. During the first days of August the division reached Chongha. On 30 July the enemy launched a naval landing of up to two companies in strength south of Phyoyenye. The landing was wiped out.

Units of the 12^th KPA Infantry Division, advancing from the area of Andon along the southeast direction, reached the east coast and cut the coast road in the area north of Phohana. As a result the 3^rd ROK Infantry Division was encircled. The enemy, striving to save this division from complete destruction, was forced to evacuate it at night by sea from the area of Upholi.

With a goal of establishing positions in the area of Phohan, the enemy sent into combat the newly arrived 38 ^th Infantry Regiment of the 2 ^nd US Infantry Division, which together with units of the ROK Capital Infantry Division launched several violent counterattacks. As a result, further movement of the 5 ^th KPA Infantry Division was halted on a line north of Phohan, but the 12 ^th KPA Infantry Division was forced to withdraw to the area northwest of Phohan.

Consequently, by 20 August the offensive of the KPA forces across the entire front was halted by stiff enemy opposition. In isolated sectors the KPA forces, under heavy enemy air and artillery strikes, were forced to abandon their positions. A particularly violent battle was fought in the area of Phohan and on the bridgehead on the east bank of the Naktong River in the area of Channae, Hyonphun, and Uikwan. The front line stabilized along the line east of Haman, the Naktong River , Indon, Hwasudon, and north of Phohan.

For that reason, the result of the offensive of the KPA forces between 26 July and 20 August saw them cover 70 to 100 kilometers and push the enemy across the Naktong River . The tempo of the KPA forces’ offensive was no more than 1-4 kilometers per day. During the course of the offensive they crushed the 2 ^nd, 5 ^th and 8 ^th ROK Infantry Divisions, inflicted heavy losses on the 1 ^st, 3 ^rd, 7 ^th and Captial ROK Infantry Divisions, the 1 ^st US Cavalry Division, and the 25 ^th US Infantry Division. Overall enemy losses were more than 50,000 officers and men.

The measures taken to halt the movement of the KPA forces up to the Naktong River , while facing enemy opposition that had made a water crossing and then set up what was called the Pusan bridgehead, were continually growing. The American command at the beginning of August sent into combat units that had newly arrived from the US , including the 2 ^nd US Infantry Division, the 1 ^st US Marine Division, as well as the 5 ^th, 26 ^th and 29 ^th Regimental Combat Teams. American aviation and naval forces were als continually becoming more active.

By the beginning of the third decade of August the situation at the front had become one complicated by strain on the KPA.

Out of 14 designated divisions 10 infantry divisions (the 6^th, 4^th, 10^th, 3^rd, 15^th, 13^th, 1^st, 8^th, 12^th and 5^th) as well the 105^th Tank Division were operating on the front lines. Three divisions were in reserve: the 7^th KPA Infantry Division in Chinju , the 9^th KPA Infantry Division which was transferred from Seoul to Hyopchon, and the 2^nd KPA Infantry Division which was moved from the area of Yendon to Sonju. The newly formed 17^th Mechanized Division was located in Pyongyang . The newly formed 16^th Tank Brigade was assembled in the area east of Hyopchon. In the areas of Chunchen and Choron were the newly forming 18^th and 19^th KPA Infantry Divisions, and two marine brigades were forming in Nampo and Wonsan .

During the course of the continuous offensive operations the forces had taken heavy losses in both men and material. Artillery losses were around 40%, and tanks and SP guns were more than 50%. By this time the average strength of an infantry division was about 30 to 50% of its tabular strength in personnel and equipment. The 1^st, 3^rd, 4^th, 6^th and 15^th KPA Infantry Divisions had taken particularly heavy losses. Thus in the 1^st and 3^rd KPA Infantry Divisions there were regiments with only 100-200 men left. The 1^st KPA Infantry Division had a total of but 63 guns and mortars, the 5^th – 141, the 8^th – 85, the 12^th – 60, and the 15^th – 92 out of a tabular allowance of 203 guns and mortars; while replacement personnel began arriving on 18 August, there were no replacements for lost armaments.

The command of the KPA was surprisingly stretched out and owed this to its continuous movement under terrible enemy aviation bombing. American aviation, having absolute air supremacy, carried out 500-1000 missions daily, launching massive strikes on the combat order of the forces, objects in the rear area, roads, bridges, and crossings. Therefore any sort of movement by truck or train during the daytime was immediately paralyzed. Railways and truck transport could only operate at night.

The KPAFAC had a total of 21 operational aircraft, which consisted of 20 shturmoviki and one fighter. Their force numbered six fighter pilots and 17 shturmovik pilots. In such a situation there was no way that they could oppose American aviation. The antiaircraft units of the KPA, in the overall difficulties, numbered no more than 80 37mm and 85mm guns, which were unable to provide cover to even the most critically important objects either at the front or in the rear area.

The total air supremacy of the enemy limited the KPA’s ability to complete rapid reorganization or maneuver of its forces and means, as well as set difficult limits on supply to the front from the rear area. The front did not receive timely and sufficient numbers of replacements, ammunition, fuel and provisions.

The enemy had concentrated 10 divisions within the Pusan bridgehead by the end of August (1^st US Cavalry, 2^nd, 24^th and 25^th US Infantry, 1^st US Marine, 1^st, 3^rd, 6^th, 7^th and Capital ROK Infantry), the 27^th British Infantry Brigade[8] and five independent regiments.

The 2^nd US Infantry Division, the 1^st US Marine Division, and the 27^th British Brigade were fully equipped with personnel and equipment. The rest of the units and formations, having taken losses in combat, were rapidly receiving replacement men and equipment.

Per the decision of the Singman Rhee government in September 1950, which was located in the territory under the control of the South Koreans and the Americans, the army was mobilizing all of the male population between the ages of 18 and 30. This mobilization permitted replacing the South Korean forces operating at the front. Thus, in early September the 3 ^rd ROK Infantry Division received 1,600 replacements. The Capital Division received 1,500 men, and the 6 ^th ROK Infantry Division received 1,000 men. The other divisions also received replacements.

The American and South Korean divisions were simultaneously receiving sufficient amounts of ammunition, provisions and fuel.

The situation at sea was likewise unfavorable to the KPA. The combined enemy naval forces were significantly increased and by 1 September numbered 190 American, British, South Korean, Dutch, and French warships (including two heavy, two light and two escort carriers, four heavy and six light cruisers, 47 destroyers, 13 fleet vessels, 42 mine sweepers, more than 60 transports, auxiliaries, landing ships, and other vessels) and 449 naval aircraft. These ships completely blockaded coastal Korea , limiting the ability of the KPA to use sea transport.

In regard to the navy of the Democratic Peoples’ Republic of Korea , by this time it had suffered such heavy losses and serious confrontation that it could no longer be considered a fleet.

Consequently the use of airspace and sea room were completely in the hands of the enemy. The enemy now had a 2:1 superiority in infantry and artillery and a 10:1 superiority in tanks.

But together with this, the American and South Korean forces, in spite of their enormous superiority in technology and their absolute supremacy in the air and on the sea, did not have the same morale qualities as the KPA. This strongly influenced the stability of the American forces in the Pusan bridgehead. Beside that, the operational initiative still lay in the hands of the North Koreans.

In studying all this and striving to rapidly complete the liberation of all of South Korea, the High Command of the KPA, in spite of its unfavorable correlation of forces, made the decision on 20 August to prepare and conduct an offensive with the goal of crushing the enemy in the Pusan bridgehead and cleansing the territory of the country from South Korean and American forces.

In executing this decision, the forces were to receive the following mission tasks:

The 1^st KPA Group Army was to use the forces of five divisions to launch a strike on the bridgehead’s right flank in the general direction of Samnojin with the mission to cut the main lines of communications of the enemy – Taegu, Pusan, and in cooperation with the 2^nd KPA Group Army, surround and destroy the enemy’s force grouping in the Taegu area, and then using the forces of one infantry division, drive the enemy from Pugokli to Uikwan.

The 2 ^nd KPA Group Army was to use the forces of four divisions to launch a strike on the center in the general direction of Yonchon, Yansan with the mission of cutting the enemy’s lines of communication Taegu-Ul’san-Pusan and in cooperation with the 1 ^st KPA Group Army surround and destroy the enemy’s force grouping, using part of its forces to support the left flank from the sea.

Force preparations for the offensive were as follows: the 1 ^st KPA Group Army was to be prepared by 30 August, and the 2 ^nd KPA Group Army was to be prepared by 1 September.

In making this decision, the KPA command saw an initial forcing of the Naktong River and breaking through the enemy defenses in the belt of the 1 ^st KPA Group Army and only after that, when they had identified success on that direction, begin the offensive with the 2 ^nd KPA Group Army.

During the preparatory period it was essential to replace the losses in the forces, bring up ammunition, reorganize the forces and prepare the units for forcing the Naktong River , which was up to 700 meters wide and up to 10 meters deep. The consequences of the continuous enemy bombardment meant that all regrouping and preparations of the forces had to take place at night, and only limited preparations during the daytime during bad weather.

The officers at all levels intensively trained their subunits, units and formations for the forced crossing of the Naktong River . They carefully studied the cycles of the river, as well as the system of fires and engineer obstacles on the enemy’s side or the left bank. Seeing that there was a lack of tabular crossing means in the forces, measures were taken to assemble primitive crossing means. In this the troops were actively helped by the population in the pre-frontal areas.

As a result of regrouping, carried out between 20 and 31 August, the forces of the Korean Peoples Army had achieved the following status.

The 1 ^st KPA Group Army had formed its strike force grouping of five divisions (the 6 ^th, 7 ^th, 9 ^th, 4 ^th, and 2 ^nd KPA Infantry Divisions) and the 16h Tank Brigade, deployed in the 40-kilometer stretch of front from Haman to Pugokli. The 10 ^th KPA Infantry Division supported the left flank of the strike force grouping on the 60-kilometer stretch from Pugokli to Uikwan.

In front of the 1^st KPA Group Army were five enemy divisions (the 1^st US Cavalry, 2^nd, 24^th and 25^th US Infantry, and 1^st US Marine), two independent American regiments, and the British brigade. On the main direction of the strike five Peoples Army divisions were deployed against three infantry divisions and two independent regiments.

The 2 ^nd KPA Group Army did not carry out a major regrouping. Its seven divisions (3 ^rd, 15 ^th, 13 ^th, 1 ^st, 8 ^th, 12 ^th, and 5 ^th KPA Infantry) were deployed along a 100 kilometer stretch of front and faced five divisions and two regiments of South Koreans.

Overall, along the 210 kilometer stretch of front the forces of the
Peoples Army had 13 divisions, one tank brigade and one motorcycle regiment with an operational density of one division per 15 kilometers of front. On this same front the enemy had 10 divisions, one brigade and five independent regiments, which corresponded to one division per 17 kilometers of front. In this it must be studied that the manning of KPA infantry divisions, as well as their armament, equipment, supply and material support, was much smaller than that of the UN forces.

The KPA forces were operating as a single echelon. For reserves in the area of the front, they had the 105 ^th Tank Division without tanks, which had to be replaced with personnel and its material component before the start of the offensive. In the area northwest of Andon was the 17 ^th Mechanized Division, which had just arrived from Pyongyang .

The enemy forces were likewise organized in a single echelon. Only isolated units formed the reserve in the Pusan area.

At 2100 hours on 31 August 1950, the forces of the 1 ^st KPA Group Army went on the offensive in the Haman-Pugokli sector. On the first night the forces made a forced crossing of the Naktong River and secured a bridgehead on the opposite bank. Overcoming stiff resistance, and repulsing American counterattacks, supported by heavy artillery fire and massive air strikes, the forces of the 1 ^st KPA Group Army covered 5-15 kilometers over eight days of stressful combat and by 8 September were fighting for YEsan and Channae.

The American command transferred the 27 ^th Infantry Regiment of the 25 ^th US Infantry Division from the TAegu area into this sector to oppose the KPA forces, as well as the 27 ^th British Infantry Brigade.

A particularly violent battle was fought for Channae, which changed hands several times. American and South Korean forces, concentrated significant forces and means in this area, drove the units of the 1 ^st KPA Group Army out of Channae and forced them to withdraw to the west. From 8 September onward the 1 ^st KPA Group Army, falling back from numerous enemy counterattacks, fought a violent battle to hold the line they had achieved.

The forces of the 2^nd KPA Group Army went on the offensive at 1800 hours on 2 September, after a short preparatory artillery bombardment.

The 3 ^rd, 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions, advancing on the right flank, broke through the defenses of the 1 ^st US Cavalry Division, the 1 ^st and 6 ^th ROK Infantry Divisions, and for two days of combat advanced 10 kilometers. Overcoming stiff enemy resistance, over the course of the next four days they continued the offensive, during which they encircled and destroyed an infantry regiment from the 1 ^st US Cavalry Division north of Taegu . As a result of continuous counterattacks by enemy ground forces and massive air strikes on the right flank of the 2 ^nd KPA Group Army, on 8 September it too was forced to terminate the offensive.

The 15 ^th, 12 ^th and 5 ^th KPA Infantry Divisions, advancing on the left flank of the group army in the general direction of Kenju, succeeded in penetrating the enemy defense and by 5 September had moved to a line north of Yonchon-Kenju-Phohan. To counter this movement, the enemy transferred the 24 ^th US Infantry Division into the area of Kenju, which launched a counterattack on the 12 ^th KPA Infantry Division and inflicted damage upon it. By 8 September the enemy had succeeded in halting further advances by the 2 ^nd KPA Group Army on this direction.

By studying the critical significance of the Pusan bridgehead, the enemy carried out exemplary stiffness in combat in order to hold it.

By making use of broad maneuver of his forces and means, the enemy was able to reinforce endangered areas in a timely manner and launch powerful counterattacks and counterstrikes, supported by massive artillery and air strikes. In the battle to hold the Pusan bridgehead American aviation carried out up to 1,500 sorties per day, providing aggressive support to their ground forces.

During these battles the Americans made wide use of naval artillery for fire support of the defending ground forces along the coast and in support of their counterattacks. Along with that, the warships carried out a systematic bombardment of the coastal and rear areas, destroying the cities of Chengjin, Sengjin, Hamhin, Inchon , as well as objects and troop concentrations of the Peoples Army in the coastal regions. Enemy naval aviation, together with the US Air Force, systematically carried out raids on the peaceful cities of Korea and launched strikes against the combat order of the Peoples Army.

For that reason, during the course of the proposed offensive launched in early September with the goal of eliminating the Pusan bridgehead the KPA forces enjoyed only insignificant success. They forced a major water obstacle on a broad front – the Naktong River – and moved along their directions for 15-25 kilometers, but they were not able to develop the offensive to carry out their assigned mission. During the course of these battles the Peoples Army inflicted significant losses on the enemy, but they themselves took significant losses of personnel and combat technology, and therefore their position as compared to that on 20 August, which was previously discussed, was much more difficult.

In creating the situation, as can be seen, it would have worthwhile to go over on the defensive or start a merciful withdrawal with the goal of getting the forces out from under the merciless strikes of the enemy. Between them, as analysis of the course of combat operations shows, after 8 September the KPA command could not demonstrate any offensive operations.

7. Overall Results and Characteristic Picture of Combat Operations by the Forces During the First Stage

Overall Results. During the course of the first stage of the war in Korea , which lasted 82 days, the Korean Peoples Army destroyed the South Korean forces south of the 38^th Parallel in a short period of time.

By deploying a general offensive along the entire front and pursuing the retreating formations of the South Korean army, as well as defeating the introduced American forces in battle, by early September the KPA had cleared the enemy from more than 90% of the territory of the country and liberated 92% of its population.

During the first stage of the war the American command had to commit a tremendous amount of aviation and naval assets, five infantry divisions, several independent infantry regiments, five artillery regiments from the reserve of the high command, and four independent tank battalions, as well as take immediate measures to resupply the South Korean forces with personnel and combat technology.

The American forces, which at that time were not in a condition to halt the strikes by the KPA, were forced to withdraw. It was only the lack of air and naval power by the KPA, as well as heavy losses in personnel and especially tanks and artillery, inflicted on them by American aviation and artillery fire, that saved them from total destruction on the Pusan bridgehead. The Americans themselves were forced to recognize that “…the North Korean army was only kept out of the Pusan area by great effort.” [9]

Characteristic Picture of the Operations of the Forces of the Korean Peoples Army. The counteroffensive of the KPA forces began as a force grouping which was created to repulse aggressive strikes by the Singman Rhee regime. The High Command of the KPA, uncovering data on the force preparations of the South Koreans, brought their own forces out of the rear area and up to the 38 ^th Parallel, deployed them in defensive lines in two echelons and allocated a reserve. On the Seoul direction, where the main enemy force grouping was concentrated, was where they put the main body of the army. By creating such a force grouping the KPA guaranteed the successful launching of a decisive strike.

The general concept of the offensive, which included the destruction of the main body of the enemy in the Seoul area with the simultaneous development of the offensive in other directions, would as a whole place them in a difficult situation, just as would the destruction of those enemy forces responsible for the entire enemy defense south of the 38^th Parallel. The shortest routes of advance for the KPA were on the Seoul direction and it was the main enemy objective. Here they had a more developed network of highways and railways, situated in the broad Seoul plain, which simplified operations by all branches of service.

Launching the main strike on Seoul from the north and additionally cutting off the entrances to Seoul from the northeast in the general direction of Suwon, with a simultaneous advance to the west and east coasts in case of success led to overwhelming the enemy defense on a broad front, encircling and crushing his main body in the area of Seoul. The offensive along a broad front limited the ability of the enemy to maneuver along that front and reinforce his forces on the direction of the main strike where the KPA was operating due to his then having to take forces from other sectors of the front.

The concept of the offensive as a whole took into consideration the forces and capabilities of the KPA as well as the forces and capabilities of the South Korean forces.

But at the same time the entry of the Americans into the war changed the correlation of forces. The Korean Peoples Army suddenly had to fight in surprisingly unfavorable conditions. Consequently after forcing the Han River the tempo of the advance of KPA forces fell back to only 4.5-5 kilometers per day.

During the course of the offensive the command of the Peoples Army had to reorganize its forces several times, but at the same time this could only be done on a limited scale. The commensurate reorganization was made more difficult due to a lack of sufficient amounts of transportation assets, strong enemy air effects, as well as the conditions of the terrain. Thus, for example, by the end of July the situation had become more difficult when it required a rapid reinforcement of forces in the area south of Yendon in order to make a swift and powerful strike against the weakly protected flank of the main body of enemy forces and to develop the offensive in the direction of Pusan . It was not possible to reorganize among the forces in the area due to the above cited reasons. As a result the command of the KPA took measures to reinforce the forces of the 1 ^st KPA Group Army, but they were too late, as the enemy had already moved major forces into the area and solidly protected his left flank.

When planning the counteroffensive the command of the KPA, formation commanders and unit commanders avoided the necessity of ensuring the superiority of forces and means along the direction of the main strike, building up strike forces to develop the offensive, as well as cover the flanks and rear from surprise attacks by the enemy. Therefore when breaking through the enemy defense the combat order on the main direction was assembled, as is correct, in two echelons, and along the secondary directions, in only one echelon. Only subsequently was a reserve created. The formations and units, advancing along the main direction, had only a narrow zone for the advance, which was correct.

Among the measures in front of the forces that halted the movement of the Peoples Army were the heavy losses inflicted by enemy air and artillery strikes. Due to a lack of reserves they were limited in their ability to gather their forces on chosen directions and the offensive, as is correct, was slowed. Replacing forces from the measly reserve created was extremely difficult, but the uninterrupted flow of supplies necessary to sustain combat and life was nearly impossible.

Analysis of the combat utilization of KPA formations shows that if at the beginning of the counteroffensive there were three divisions in the second echelon and one in reserve of the High Command, then by the end of June three of the four divisions had been committed to combat. [10] In this the operational reserve, as correct, was not established. The majority of the divisions were carrying out continuous combat lasting two and more months. In August the forces gathered to strengthen the operational forces were nearly exclusively formed of newly created formations. In September all of the KPA forces were engaged in combat. Only the 105 ^th Tank Division remained in reserve, albeit without its materiel component, along with the newly-formed 17 ^th Mechanized Division.

During the course of the offensive the KPA forces were used to seize and hold, establish encirclements and destroy enemy units and subunits. Holding areas required more and more frequently unexpected sizes of subunits, starting with platoon, company, and on occasion battalions and regiments. But at the same time wide employment of these methods was operationally not possible. In a number of cases attacks were carried out from the front, combat took on a prolonged nature, and the enemy was not destroyed but instead pulled back. This was particularly obvious in the examples of combat operations in the Seoul area, when due to the slow movement of units of the 3 ^rd and 4 ^th KPA Infantry Divisions and the 105 ^th Tank Division, coupled with the unsatisfactory performance of the 2 ^nd KPA Infantry Division and the motorcycle regiment, the enemy was not destroyed in the Seoul area. They were not able to completely destroy the 24 ^th US Infantry Division in the Taejon area. Similar underestimation was found in the combat operations of the 2 ^nd KPA Group Army along the Yongu-Andon line where KPA forces fought heavy battles for nearly 15 days, striving to use frontal assaults to seize strongly defended enemy strong points.

At the beginning of the war combat operations were mainly carried out in daylight. But at the same time, by mid July and in view of the absolute air supremacy of the enemy, KPA forces had to switch over nearly exclusively to night combat operations. While it did not halt the successful movement of the KPA forces, it significantly slowed down the speed of the offensive. The most typical of force operations by the Peoples Army at night was the surprise, swift attack on the enemy, often carried out without any artillery preparation.

During the course of the offensive the forces of the Peoples Army had to make forced crossings of many rivers, including major ones like the Han, the Kim, the Ham and the Naktong. In most cases the rivers were forced after short preparations, but in some cases they had to be forced from the march. Forcing the river was normally carried out on a broad front, at night, with preparatory artillery fires, and most often than not by units which had to fire using direct fire methods. The infantry and light armaments were consequently lacking tabular crossing means, so they made use of boats, rafts, etc. but the tanks, SP guns and artillery had to cross on ferries captured from the enemy or by restoring the bridges. On occasion they made use of underwater bridges.

A major role in the success of the infantry was played by the tanks, SP guns and artillery.

During the first stage of the war the tanks and SP guns were used almost exclusively for direct support of the infantry, which under actual conditions was absolutely correct. But at the same time the use of tanks had its shortcomings: the artless lack of organizing artillery support in tank operations; the poor engineer support for the offensive, and subsequently the tanks would suffer losses in enemy mine fields; and the indecisive actions of the tankers themselves.

With a limited amount of artillery, the main type being divisional, artillery force groupings were created under the noted difficulties, especially under conditions when the infantry regiments frequently were operating on independent directions. Therefore regimental artillery groups consisting of no more than two battalions were normally created just for the infantry regiments operating on the main direction. The regiments operating on the secondary directions were normally reinforced by only a single battalion of artillery.

When breaking through the enemy defense preparatory artillery fire was used for the attack, and then corresponding fire support for tanks and infantry during the attack and accompaniment of their operations to the depths of the enemy defense. The duration of artillery preparatory fires depended on the nature of the enemy defense, and based on the available artillery and ammunition varied from 20 to 40 minutes. Support for the tank and infantry attack was conducted by concentrating fires to a depth of 2.5-3 kilometers. Accompanying fires for the infantry and tanks for combat in the depths of the enemy defense likewise corresponded with subsequent concentrated fire, but also making use of those guns which were accompanying the infantry in their immediate combat order.

During the time of the successful offensive and beyond formation and unit commanders did not always pay sufficient attention to the timely displacement of their artillery, as they provided it no assistance. All of this led to the fact that the unit or formation, running into stiffening enemy resistance in the depths of the defense, found itself in a situation without any fire support. This took a long time to bring up the artillery. According to the measures for developing the offensive and after acquiring experience, this shortcoming was gradually corrected. With the entry into the war of the US armed forces and the establishment of absolute air superiority by American aviation the conditions for moving artillery and the ability to maneuver it were much more limited and the artillery took heavy losses.

Due to its small numbers, even in the first stage of the war KPA aviation did not play a significant role. During June ground attack aviation made 44 sorties, 46 in July, 4 in August, and 4 in September for a total of but 98 sorties with an overall time of 100 hours. Between June and August fighter aviation made 222 sorties, shooting down 45 enemy aircraft.

On 25 June the DPRK Navy successfully carried out a naval landing near Kannin, which was conducted without loss. Later the fleet, due to its small numbers, did not take part in active combat operations. Coastal and antiaircraft artillery and marines organized the defense of important naval bases. The artillery fought against enemy aircraft and ships that were carrying out bombardment of naval bases and coastal installations.

The air defense of objects in the rear was poor due to their small numbers. For this reason, on occasion the antiaircraft batteries were used on the front lines to participate in repulsing counterattacks from infantry and tanks and fire on ground targets.

The system of command and control of the forces, corresponding to peacetime, did not provide for timely deployment of the controlling organs necessary to organize continuous and reliable leadership for forces during wartime. The great distance at the start of the war from the General Staff to the front severely impacted immediate command and control of the formations. After organizing the frontal headquarters and the group army headquarters, they were given control over the combat operations of the forces at the front. Planning and organization of the defense of the western and eastern coasts remained in the hands of the General Staff. But at the same time all of these headquarters were just knocked together and none of them had sufficient communications means. The General Staff continued to let them remain weak and did not have a fully fledged command and control organ for the High Command. The group army headquarters, having a large number of formations subordinate to them (5 to 7), could not provide harmonious leadership and therefore command and control of the forces was never reliable.

The command and control situation at the division to regiment level was no better, which was explained by untrained staffs and a shortage of communications means. Some formation commanders went two or more days without any information on their units. The characteristic failings of command and control at the beginning of the war were these: artless staffs that were formed in a hurry and sent to the forces based on commanders’ decisions; a lack of skills in providing continuous support to cooperation among the arms of service, units and subunits by a number of formation and unit commanders; artless commanders and chiefs of staff in the skills needed to establish a command post; underestimates by several commanders on the role and place of the staff in command and control of contemporary combat and quick personal command and control without a staff; lack of timely reporting and information on the locations of one’s own forces and those of the enemy; poor organization of reconnaissance.

During the course of combat operations there were also failings in the work of the Peoples Army rear services. The rear service organs could not organize regular supply of the forces and evacuation of the wounded. To a significant level this was explained by the lack of sufficient transportation assets and the strong effects of American aviation on their supply routes. But together with that is the place where there was a failure to set up an organized order: a lack of dissemination and a lack of skill in organizational work. There were isolated cases at the front where shells arrived without fuses, machine guns without stands, etc.

Characteristic Picture of the Operations of the Forces of the South Korean and American forces. The command of the South Korean army was not able to pay sufficient attention to organizing the defense. Therefore, as a result of the preparatory artillery fires and subsequent strikes against them by the KPA forces the majority of their strong points and nodes of resistance on the first line of the South Korean defense were taken even in the first few hours of the offensive. The enemy’s defense was shattered and cut down to only isolated pockets of resistance. These pockets of resistance, defended by what were mostly demoralized troops not possessing a high moral spirit, were rather quickly eliminated by the advancing KPA units.

The enemy attempted to restore his shattered system of defenses by the means of bringing up reserves and the second echelon, striving to throw back the KPA forces with counterattacks from a starting position. The counterattacks were carried out by battalion to regimental sized forces, and in some isolated sectors by two regiments with support from artillery fire. The terrible battle fought on 25 June and in some directions lasting to 26 June turned out to be decisive during the course of the fight for the main defensive belt. The South Koreans took heavy losses in these battles and were forced to withdraw. While withdrawing, they strove to strengthen favorable lines of defense, the main type being road junctions, as well as hills covering the main roads as well as the sides of valleys and banks of rivers. But as is correct, these lines were quickly knocked out.

With the entry of US forces into the war in Korea , the American command took measures needed so as to stop the advance of the KPA forces and strengthen the favorable lines of defense. In striving to play for time to get their main body up to these defenses, they sent reinforced detachments forward, supported by air operations.

During the time that American forces were withdrawing, combat operations took place on a broad front (60-70 kilometers per division), which concentrated their main effort along important roads. The speed of the withdrawal of American forces varied from 7 to 20 kilometers a day. The retreat of units and subunits was carried out, as is correct, by truck.

While retreating, there were failures in the organization of cooperation between the arms of service and neighboring units, especially cooperation between the Americans and South Korean forces. On occasion there were times when units would not know where their neighbor was located. For example, In the Phohan area the Americans fought with the South Koreans, inflicting heavy losses on each other. Communications between the Americans and South Koreans was only supported later. During the retreat the American command would frequently leave the South Koreans to their fate.

By 20 August the American and South Korean forces had withdrawn to a naturally favorable line of defense that formed what was called the Pusan bridgehead.

By the time they pulled into the Pusan bridgehead area the width of the belts held by American and South Korean formations and units was significantly reduced. On average each infantry division cover a front of 20 kilometers.

The defense of the UN forces in the Pusan bridgehead consisted of a system of strong points built in villages, on hills and at road junctions. The interval between the strong points was covered by fires and various obstacles.

The combat order of the forces was formed without deep echelonment, normally in only a single echelon with an allocated reserve; at division, forces of up to battalion strength; at regimental level, a company.

In the defense the American command, using a widely deployed network of highways and trucks, could maneuver forces relatively rapidly, taking them from quiet sectors and moving them to the direction of the threat.

The infantry of the South Korean army, having a relatively large number of recoilless rifles and rocket weapons, did not make skillful use of them. Antitank defense was set up in too shallow a depth. Antitank artillery was deployed in groups of 4-6 guns, and in the area of Yidenpu and Seoul they were concentrated in nodes of 8-12 along narrow sectors. During the course of combat operations it turned out that the 60mm rocket weapon was ineffective against KPA tanks, and therefore it was quickly replaced with the 88.9mm antitank weapon.

At the start of combat operations in Korea the American forces had an insignificant number of tank subunits. The reason for this was that there was an underestimation by a number of military leaders in the US Army about the role of tanks under conditions like those in Korea , which was basically a mountainous country. They felt that tanks could not find wide application in Korea or they would only be able to carry out a very limited number of tasks. The successful use of tanks by the Peoples Army made the American command immediately send tank subunits to Korea . Initially they sent over tank subunits from Japan , which were armed with the obsolete Chaffee light tank and the Sherman medium tank. But at the same time these tanks were ineffective. Then they began to send over tank subunits from the USA armed with the superior Pershing and Patton tanks.

During the withdrawal of American forces to the Pusan bridgehead tanks wer used to cover their exit from combat and subsequent retreat of the infantry. Beside that, tanks were used to support retreating columns against partisan attacks, during which part of the tanks would move at the head of the column.

In the defense tanks in infantry regiments were used to reinforce infantry antitank defenses, deploying them among the combat order along tank accessible directions, and the divisional tank battalions were kept as the division commander’s reserve to use to support infantry during counterattacks.

Artillery was used during combat operations in the first stage of the war and organizationally assigned to infantry divisions and regimental combat teams, as well as artillery reserves of the high command. [11]

The experience of combat in the first days of the war showed that South Korean army artillery was not able to respond to infantry requests in full measure. The command of the South Korean army could create sufficient density of artillery fires only along the main axis of the retreat, or on important roads. In striving to make up for the insufficient artillery firepower, from 27 June onward the American command gave part of the missions that should have been carried out by artillery to aviation.

During the retreat of American forces to the Pusan bridgehead, in most cases field artillery was not deployed and did not provide the necessary support to its own infantry. Moreover, the artillery, as is correct, withdrew in the first group, and as a consequence it frequently meant that their own forces were left without artillery cover. In those situations when field artillery was forced to provide immediate cover to withdrawing forces it usually deployed along roads. As soon as the slightest threat materialized from the ingress of Peoples Army forces into the flanks or rear of the American forces, the artillery would displace from their fire positions and immediately withdraw to the rear.

During the battles for the Pusan bridgehead the artillery was much better organized for use.

In order to support the operations of infantry regiments, they were allocated 105mm battalions, but the 155mm howitzer battalion was used for general artillery support to the division. Each infantry regiment was supported by a battery. The automatic weapons antiaircraft battalion of the division was deployed among the howitzer battalions with one battery per battalion and used for the most part to fire at ground targets.

When repulsing night attacks from the Peoples Army, the American artillery normally used barrier fires. Counterattacks by American forces were supported by massive artillery and aircraft strikes.

Cooperation between the artillery and infantry at regimental level was organized by the infantry regiment commander and the commander of the artillery battalion.

The primary mission for engineer support in combat operations was normally carried out by the division sapper battalion, as at this time engineer units of the reserve of the high command were used in the rear area of the first echelon forces.

During the retreat sapper subunits destroyed roads and bridges, blew up buildings in cities, and laid engineer obstacles and barriers, the majority of which were antitank.

At the beginning of the war antitank mines were not used. They began to appear in Korea at the beginning of August. The lack of mines, in the opinion of the Americans, was one of the mistakes of the American command at the start of combat operations. Antitank mines were introduced as a measure by which the forces could mine important roads and set up “booby traps.” Reasonably wide use of antitank mines was used during the defense of the Pusan bridgehead.

From the very start of the war in Korea the American command had paid a great deal of attention to fighting for air superiority. Beside that, the efforts of American aviation were focused on carrying out missions to isolate areas of combat operations and provide direct support to ground forces.

The missions to isolate areas of combat operations were carried out by means of launching strikes against lines of communication, railway nodes, bridges, warehouses, railway trains and trucks, against the reserves and groups of troops and technology at the tactical and operational depth.

The missions to provide direct aviation support to ground forces was carried out by means of launching ground attack and bombing strikes on troops, artillery positions and tanks.

The planning and control of aviation cooperation with ground forces corresponded with specialized organs – combined operations centers, in which officers from the operations and intelligence sections of the US 8^th Army and 5^th Air Force worked together.

The use of aviation during the first stage was characterized by sufficiently precise cooperation with ground forces.

From the first days of the armed conflict in Korea the navy took an active part in combat operations, with its primary mission being first and foremost to blockade the Korean seacoasts. In this the western coast was primarily blockaded by British Commonwealth vessels, and the east coast by Americans, who fought with the DPRK Navy, fired on coastal settlements, and cooperated with their forces during operations on the coastal directions. Along with that the navy provided naval landings, primarily at the tactical and diversionary force levels, as well as provide for the evacuation of South Korean forces which were threatened with destruction. Naval aviation, in cooperation with the USAF, carried out bombing of the combat order of the KPA and rear area objects in Korea .

[1] Note: This is an updated and edited version of the original 1954 text, and the authors have inserted post-1954 information into the text where it is relative. This expands and modifies many of the original conclusions as well as provides a better view of UN operations with generally the correct units and designations for the opposing side. Translator.

[2] Note: this document uses the Soviet meanings of words, to wit: formation – division level forces; unit – regimental level forces; and subunit – battalion level and below forces. Translator.

[3] Note: from this point on all units will be identified by letters: e.g. KPA, ROK, CPV, and US to prevent confusion. Translator.

[4] Published in New York in 1956, pp. 323-324.

[5] After taking Seoul this formation was renamed the 105^th Tank Division.

[6] The organization of KPA command and control at the end of June 1950 is shown in Appendix 28.

[7] The organization of KPA command and control at the end of July 1950 is shown in Appendix 29.

[8] This unit arrived in Korea from Hong Kong on 29 August 1950.

[9] T. K. Finletter, Force and Policy, Moscow , Foreign Literature Publishing, 1956, page 158

[10] A chart of combat utilization of KPA formations is presented in Appendix 30.

[11] Beside organic artillery assets each regimental combat team was reinforced by a battalion of field artillery.