Military Historical Library

Chapter 3. Counteroffensive by American and South Korean Forces and Entry into the Northern Region of the DPRK
(Second Stage of the War – 15 September 1950 to 24 October 1950)[1]

The command of the US armed forces, afraid that the remnants of the South Korean forces and American units could finally be destroyed and the Peoples Army completely liberate Korea, placed all of their efforts into halting the further movement of the KPA forces. To this end, they continuously moved new ground forces into Korea at Masan , Kenju, and Taegu . The US Navy had totally blockaded all the coastline of Korea by early September and kept all of the lines of communication of the KPA running along the coasts under constant check. During August and the first half of September enemy aviation had continuously inflicted damaged via bombing strikes on the combat order of the forces, their headquarters, and their rear area.

The KPA forces were consequently up against significantly superior enemy forces in the area of technical means of combat, having suffered heavy losses from enemy aviation and artillery fire. Due to the lack of aviation and an extreme shortage of artillery and tanks units and formations were forced to carry out offensive operations only at night.[2] Command and control of the forces of the group armies was disrupted. In making numerous attempts to regain the offensive, the KPA did not only not throw them back into the sea, but it was forced due to the effects of heavy counterstrikes by the American and South Korean forces to retreat on some sectors of the front to the right (west) bank of the Naktong River, halting further offensive actions and by mid September went over to the defense on the lines they had achieved.

The South Korean forces of the UN, having finally halted the KPA offensive on 8 September, moved to carry out immediate preparations for the counteroffensive with the goal of crushing the DPRK forces and occupying all of the territory of Korea .

In planning the counteroffensive, the American command of the unified forces, located in the area of Kenju, Taegu and Pusan , and the I and IX US Corps and I and II ROK Corps were subordinated to the 8^th US Army. To conduct a naval landing operation the X US Corps was created by the Americans.

The concept of the operation was based upon simultaneously striking with the ground forces from the Taegu area and a naval landing which would come ashore at Inchon, move in the direction of Chungchen and Anson and encircle and destroy the main body of the KPA forces in the southern part of Korea and, once the situation sharply changed in their favor, end the war by advancing to the borders.

For the offensive from the Taegu area – the I US Corps (the 1 ^st US Cavalry and 24 ^th US Infantry Divisions and the 27 ^th British Infantry Brigade) and the II ROK Corps (1 ^st, 6 ^th, 7 ^th and 8 ^th ROK Infantry Divisions). All six infantry divisions and the one infantry brigade would be reinforced with a significant number of tanks and artillery.

For the naval landing – the X US Corps (the 1 ^st US Marine Division and the 7 ^th US Infantry Division, a British Commando detachment, and units of the South Korean forces). The 7 ^th US Fleet was allocated to provide direct support to the naval landing operation.

In accordance with the general concept of the operation, the following missions were allocated to the UN and South Korean forces:

The I US Corps received the mission to break through the enemy defenses of the 1 ^st KPA Group Army northwest of Taegu , force the Naktong River , and in cooperation with the II ROK Corps destroy the units of the 2 ^nd, 10 ^th and 3 ^rd KPA Infantry Divisions. During the course of the further advance in the direction of Kimchon, Taejon, Anson the forces of this corps would move to divide the KPA forces by linking up with X US Corps at Anson and then destroy the forces of the 1 ^st KPA Group Army.

The II ROK Corps, in cooperation with the I US Corps, had to break through the defenses of the 2 ^nd KPA Group Army on the front Uikwan-Yonchon, destroy the units of the 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions, and, after deploying their forces for an offensive in the direction of Guni-Yechon, destroy the forces of this group army. Ultimately the formations of this corps would force the Naktong River on the front Hamchan-Andon and continue the offensive to the north in the general direction of Tanyan-Chunchen.

Operations by the I US Corps and II ROK Corps would be supported by the offensive of the I ROK Corps on their right flank along the east coast in the direction of Yondok-Phyonyae-Yayan-Koson and on the left flank by the offensive of the IX US Corps towards Kochan and Chinju . The 5 ^th RCT and a battalion of Marines were assigned the task of operating along the southern coast of Korea .

The mission of the X US Corps was landing in the port of Inchon , destroying any KPA units resisting them there, and taking the port and city. In developing the offensive to the eastern and southeastern directions the forces of this corps had to take Seoul , and then link up with the I US Corps advancing from the Taegu area.

Ultimately the X and I US Corps would advance in the direction of Kaysen and then move to the 38 ^th Parallel.

The advance of the UN forces in South Korea was supported from the air by 1,120 aircraft (170 heavy bombers, 180 medium bombers, 750 fighter-bombers, and 20 reconnaissance aircraft). In this up to 500 aircraft and helicopters were allocated for the support to the landings of X US Corps in the Inchon area alone.

The overall command on land, sea and air had to be combined under the commanding general of the unified armed forces of the UN in Korea , General McArthur.

Together with the special missions and significant territorial break between the X US Corps and the I and IX US Corps, for more precise organization and correct command and control of troops operating in different areas a “Southern” command was created, headed by 8 ^th US Army commander General Walker, and a “Northern” command which was under the immediate command of General McArthur.

Preparations for the counteroffensive began at the end of August even while the tough defensive battles were being fought by South Korean and American forces.

By early September six American divisions had been transferred from Japan, the USA and other areas to Korea under difficult circumstances, as well as one British brigade, nine tank battalions, 27 field artillery and 105mm and 155m howitzer battalions, nine antiaircraft battalions, 800 mortars and 1,700 recoilless rifles and bazookas. By this time in Korea independent infantry battalions from Australia and the Philippines also began to arrive. The size of the average infantry battalion reached 1,200 officers and men. Beside that, as a result of mobilization in South Korea during September 1950 more than 25,000 men had been sent to their forces as replacements.

In early September the American command moved to transfer its forces and concentrate its main body on the direction of the main strike. The 7 ^th ROK Infantry Division, which had been shattered in combat at Seoul , was restored and on 11 September took its place in the front lines of operational forces in the area of Yenchon. The 24 ^th US Infantry Division, brought back up to strength, was immediately moved from the area of Kenju to the direction of the main strike west of Taegu . This area also saw the concentration of the 1 ^st US Cavalry Division and the 27 ^th British Infantry Brigade, and east of Taegu , the 1 ^st, 6 ^th and 8 ^th ROK Infantry Divisions.

As a result of the measures conducted in regrouping and significantly reinforcing the forces with technical means for combating the enemy, by the beginning of the offense a total of ten infantry divisions had been concentrated in the Kenju-Taegu area, as well as one independent brigade, three regimental combat teams, one Marine regiment, three independent infantry battalions, four independent tank battalions, and a significant number of artillery assets.

Preparations for the naval landing operation, just as for the offensive from the Pusan bridgehead, began even the first stage of the war.

In the first half of July 1950, when heavy combat was taking place along the Han River and the South Korean forces of the interventionists were retreating to the south from the 38 ^th Parallel, the American command moved to transfer units of the 1 ^st Marine Division and the 1 ^st Marine Air Wing from the USA to Japan, and in August they transferred the 7 ^th US Infantry Division with reinforced personnel. During July and August 1950 all of the efforts were on concentrating tank transporters in the waters of Japan and Korea as well as landing vessels and cargo ships chartered from private companies.

In August 1950 several exercises were conducted in the Gulf of Sagami (west of Tokyo Bay ) in naval landings, in which warships, landing ships, aviation and ground forces all participated. [3]

In the period of the second half of August to the middle of September the American command carried out landings of diversionary reconnaissance groups on the east and west coasts of Korea . The strongest of these groups was landed in the area of Phohan on the east coast and in the Kunsan area on the west coast, as well as on islands in the area of Inchon . The mission for these groups included the conduct of reconnaissance on the coastal defense system, the destruction of radio stations, railway bridges and tunnels and other objects, and also the capture of individual islands and creation of strong points there.

From 25 August to 5 September the USAF carried out more than 5,000 sorties. Bombing strikes were launched primarily against lines of communication, industries and military objects, cities, and railway nodes located in the territory liberated by the KPA as well as those forces deployed along the Naktong River valley and west of Masan .

In the first half of September all of the preparations for the offensive from the Taegu area as well as the naval landing operation were fully completed. By 15 September the forces had taken up their starting positions in the following force groupings.

At the front from Kosan to Sil’won was the 5 ^th RCT and Marine subunits. To the north, on the front from Sil’won to Chonnaedon, the defense was in the hands of the IX US Corps with two American infantry divisions. The I US Corps with two American infantry divisions and one British infantry brigade had taken up their starting positions for the offensive on a narrow 15 kilometer sector from Chonnaedon to Sindon. The 2 ^nd ROK Corps with four infantry divisions took up their starting positions for the offensive on a 50 kilometer front from Sindon to Yonchon. The 1 ^st ROK Corps with two infantry divisions was defending on a 40 kilometer front from Yonchon to Masandon.

All corps were deployed in a single echelon, as no second echelon was created nor was any reserve allocated. The only reserves in the 8^th US Army was the 29^th RCT, concentrated in the area of Tutomae, and the 26^th RCT, deployed in the area of Ul’san. The units of the 1^st Marine Division in the Pusan area had withdrawn from combat, as they were designated to carry out the naval landing operation.

For that reason, along the direction of the main strike on the front from Chonnaedon to Yonchon (around 70 kilometers) were six infantry divisions and one infantry brigade, reinforced by three artillery battalions from the general reserves and three independent tank battalions, which meant one division per ten kilometers of front on average and an operational density along the entire front of more than 20 kilometers per division.

By the start of the offensive the American infantry divisions had created temporary tactical groups, each of which had one infantry battalion and 10 tanks, reinforced by artillery. The mission of these groups was the direct pursuit of KPA forces in case they began to withdraw, capture and hold ground until the main body could reach important objectives and lines, and quickly move in the ordered direction to link up with the formations and units coming from Inchon . Operations of these groups were to be supported by aviation.

The naval forces, special and other vessels which were allocated for the landing operation, were formed into a special task force by the 7 ^th US Fleet and were under the command of Vice Admiral Strabel.

In all there were 260 ships and vessels which had to take part in the naval landing operation. Landing the troops on the coast would be supported by naval aviation and naval gunfire from the warships.

All of the naval forces were dispersed among various ports and bases in Japan and Korea , from which the naval landing would depart at night, beginning on 6 September in order to begin movement towards the landing area.

The formations and units designated to participate in the naval landing operation were fully manned, had undergone special training exercises and were completely prepared to carry out their assigned missions. On 10 September 1950 these forces numbered in excess of 40,000 men.

By mid September the forces of the KPA were in the following positions. Opposing the interventionist forces along the Naktong River line were the 1 ^st and 2 ^nd KPA Group Armies. The 1 ^st KPA Group Army was defending the riverbank from Koson to Masan and further along the line of the right bank of the Naktong to Uikwan. The 2 ^nd KPA Group Army, having repulsed enemy counterattacks, was carrying out combat operations along the line north of Taegu , Sinnae, Yonchon and Phohan. Opposing the strike group of the enemy forces along the Chonnaedon-Yonchon line were units of the 10 ^th, 3 ^rd, 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions, which had suffered heavy losses in previous battles and had significant shortages in personnel and combat technology.

At the start of the offensive the actual KPA divisional strength was no more than 50% of its tabular strength.

The KPA forces were composed into a single echelon. There were no second echelons or reserves at division level. There was no way to improve the terrain from an engineer standpoint. Tank threat directions were not covered by artillery or engineer obstacle means.

The defense in the Inchon area was even weaker. By the moment that the landings began forces in the area were insignificant: one newly forming marine regiment consisting of three battalions, a signals company, a sapper company and an artillery battalion; police and independent infantry battalions, with a total strength of around 3,000 men, seven 76mm guns and six 37mm antiaircraft guns.

Wolmi-do Island , covering the port from the west and connected to the mainland by a causeway, was defended by but two companies of marines, reinforced with three 76mm guns and two 37mm antiaircraft guns. Defense works in the Inchon area amounted to 34 pillboxes and an insignificant number of open fighting positions for batteries and other means of fire. But even there the earthworks were only 40-50% complete. 26 tethered naval mines were all that covered the approaches to the port from the sea.

As for the reserves along the 38 ^th Parallel, which could be called up to turn back the enemy offensive within 2-3 days, the High Command of the KPA had the 17 ^th KPA Mechanized Division units (north of Andon) and subunits of the newly formed 1 ^st Tank Brigade (in the area southeast of Kimchong.)

The 70 ^th Independent KPA Infantry Regiment and independent tank regiments, which were still forming in the area of Suwon , were too far from the front lines. In the area of Seoul was the 18 ^th KPA Infantry Brigade, consisting of six battalions and a sapper engineer subunit.

North of the 38 ^th Parallel, in the area of Sariwon, Singyae, Nampo and Pyongyang, as well as in the Wonsan and Hamhung areas, were newly forming units and formations, but they were greatly underequipped and undermanned, and could not be used in the first days of the enemy offensive.

Due to a lack of weaponry the 25 ^th and 27 ^th KPA Fortified Region Brigades could not be used, who were concentrated around Chorwon and Kaysen.

The correlation of forces and assets on 15 September across the entire front is show in Table 3.

Element	KPA Forces	US And ROK Forces	Ratio
Divisions	13	(12) 36*	1:3
Tanks	40	500	1:12.5
Guns and mortars	811	1,634	1:2
Aircraft	-	1,120	Absolute enemy air superiority
* Note: Due to the fact that the strength of the average KPA infantry division was no more than 4,000 men, whereas UN force divisions numbered 12,000-14,000 officers and men, the number of enemy divisions outside of the parentheses is equal to three to one over the KPA. Inside the parentheses is the actual number of divisional formations.

The correlation of forces and assets along the direction of the main strike northwest from Taegu is shown in Table 4.

Element	KPA Forces	US and ROK Forces	Ratio
Divisions	Around 4	(7) 21*	1:5.2
Tanks	20	360	1:18
Guns and mortars	236	Around 1,100	1:4.6
* Note – same as for Table 3

Even less advantageous for the Peoples Army was the correlation of forces in the Inchon area. By the moment that the landing took place the American command estimated that they had a 20 to 1 superiority in troops, artillery and tanks and absolute air and naval superiority.

For that reason, the presence of major American naval forces in the Pacific basin, as well as aviation and a likewise significant number of ground forces with an advantageous geographic position on the Koran Peninsula gave the UN forces a wide number of opportunities to conduct landing operations on a large scale, especially along the western coast in the areas of Inchon, Kunsan and Nampo.

The KPA command was not able to assess the threat and had organize a reliable anti-landing defense, orient commander at all levels towards the possibility of a landing and at the earliest opportunity take measures to destroy landing forces on the sea and on the land.

But at the same time analysis of the situation shows that in spite of tremendous objective difficulties they did not pay sufficient attention to the defense of the west coast, and that proved disadvantageous for KPA forces as the later development of events was to show.

Loading the naval landing on ships and departure of the landing detachments from the assembly point began on the night of 7 September. The landing was preceded by many very careful aerial and naval reconnaissance sorties and a mighty long-term shore bombardment by artillery and aircraft to work over the area designated for the landing site.

On 10 September two aviation groups of 30 aircraft each bombed Wolmi-do Island , which covered the entrance to the port of Inchon . On 11 and 12 September a group of 50 B-29 bombers hit the island’s garrison. On 13 September up to 300 aircraft conducted continuous operations against the combat order of the KPA on the island and in Inchon itself. Simultaneously up to 40 warships placed the island under intensive naval gunfire.

On 14 September, all of the forces allocated for the landing operation arrived in the Gulf of Kanwaman .

As a result of the continuous aviation and artillery working over of the garrison on Wolmi-do Island , they suffered heavy losses. Only two guns and one heavy machine gun survived. One more company was rushed out onto the island on the night of 14 September, which together with the remnants of the garrison turned back all enemy attempts to land there on 14 September.

On the night of 15 September the High Command of the KPA sent an infantry regiment there from the newly forming 18 ^th KPA Infantry Division. [4]

On 15 September, after a 45-minute air and naval bombardment, the leading units of UN forces, meeting no resistance, as the entire garrison defending the island had been nearly completely killed, landed on the coast and supported the landings of the 1^st Marine Division immediately into the port.

The attack on Inchon began during the second half of the day with the South Korean and American forces hitting them simultaneously from the west, north and south.

Putting up stiff resistance, the remnants of the KPA subunits, after taking heavy losses from aviation and enemy artillery fire, were forced to retreat to the east. On 16 September the enemy had completely taken the port and the city and had moved 4-6 kilometers to the east.

The defenders of the port and city of Inchon had acquitted themselves with glory. The sailors defending Inchon itself had shown exceptional heroism. It was only after a five-day bombardment from the air and the naval gunfire, when all of their artillery weapons, machine guns, and other means of fire had been knocked out and a significant part of the glorious defenders of the city had fallen as heroes that the enemy was able to take Inchon.

During 14-16 September American Naval aviation continuously bombed KPA forces in the area of Seoul and units moving towards Inchon . The regiment from the 18^th KPA Infantry Division sent to Inchon was thus scattered and not able to help the defenders of the city.

With the seizure of the city and port of Inchon the UN forces turned to an offensive in the direction of Seoul with their main body and also sent part of their forces towards Kimpo, the largest airport in Korea , as well as Suwon , where another air base was located. By 17 September the only forces battling with the advancing enemy on these directions were the sapper engineer subunit and units of the 18 ^th KPA Infantry Division.

On the night of 17 September, one engineer obstacle detachment created from the sapper engineer subunit entered the Fuhey area and set up 500 antitank mines along the road from Inchon to Kimpo. Work was carried out on the east bank of the Anchunchon River to create a defensive line. But at the same time there were not sufficient forces to carry this out.

Together with the rising threat of an enemy breakthrough into Seoul the High Command of the KPA made the decision to launch a counterattack on 17 September into the flank of the enemy, who was advancing on the Han River, using the forces of the 70 ^th Independent KPA Infantry Regiment and independent tank regiments which were located in the Suwon area. But these measures were not sufficient, as the enemy forces, after fighting the tank battle, destroyed the subunits of the 18 ^th KPA Infantry Division as it was moving from Totsugenri to Fuhey, burning out 16 tanks, and on 17 September they punched through weak covering forces and took Kimpo airfield. They simultaneously made a forced crossing of the Han River northwest of Seoul and moved towards Yendinpo. After taking Kimpo airfield the American command rebased combat aviation there (the 1 ^st Marine Air Wing.) Starting on 19 September transport aviation began bringing in weapons, ammunition and rations to this airfield.

Together with the movement of the forward enemy units into the area of Kimpo and Yendinpo the KPA command was forced to send two battalions of the 70 ^th Independent KPA Infantry Regiment and 10 tanks there from Suwon . Only one battalion remained at Suwon , which could not mount even a small counterattack.

In order to organize the defense of the Seoul direction, on 17 September the Seoul group of forces was organized under the command of Minister of National Defense Tsoy Yen Gen. The consist of this group include three fortified region brigades, nine independent infantry regiments, four tank regiments of 15 tanks each, a police regiment, and a number of special subunits. Beside that, by order of the High Command of the KPA the 1 ^st and 9 ^th KPA Infantry Divisions and 17 ^th Mechanized Divisions were withdrawn from the front and sent to Seoul .

But at the same time, due to the poor organization of communications, the lack of precise command and control and the understrength status of the allocated forces, by 19 September only the police and border regiments, the 78 ^th and 70 ^th Independent KPA Infantry Regiments, two regiments from the 18 ^th KPA Infantry Division, and railway and sapper engineer battalions had been amalgamated as the Seoul group of forces. Prior to the arrival of the remaining forces, these units and subunits were forced to move directly out and take up the defense of the right bank of the Han River from the junction with the Imjin River to Hisyu with the police and border regiments, from Hisyu to the railway bridge with the forces of the 78 ^th Independent KPA Infantry Regiment, from Yendinpo to Hori with the two regiments from the 18 ^th KPA Infantry Division and the two battalions from 70 ^th Independent KPA Infantry Regiment. The railway bridge over the Han River was defended by the railway troops and sapper engineer battalions.

The suburbs of Seoul were fortified and barricades were built. The workshops and shops at selected factories were used to produce antitank and antipersonnel mines, hedgehogs from rails, metallic anti-turret barriers and other obstacles. More than 10,000 residents of the city were turned out to work on the defenses, showing exceptional patriotism. By 22 September more than 100,000 citizens were mobilized to defend the city by supporting the forces, and they built more than 700 barricades.

By this time the UN forces had forced the Han River northwest of Seoul in the sector south of Hisyu. For crossing their infantry and light artillery they used GMC amphibians, but the tanks had to use self-propelled tank transporters. Overall by 22 September 65 armored vehicles had been moved to the left bank of the river.

On 16 September, after a short but powerful preparatory air and artillery bombardment, the enemy launched his main strike from Taegu to the north and northwestern directions.

The formations of the I US Corps, who were launching the main strike in the direction of Kimchong-Taejon-Seoul, during the course of six days of heavy combat broke through the defenses of the 3 ^rd KPA Infantry Division in the area of Uikwan, capturing that village and forcing the Naktong River south of Uikwan. The 13 ^th and 3 ^rd KPA Infantry Divisions of the 2 ^nd KPA Group Army and the 10 ^th KPA Infantry Division of the1st KPA Group Army, who were occupying the defense on a broad front and did not have well-equipped defensive positions, took heavy losses from enemy artillery and aviation bombardment and could not halt the offensive.

The formations of the II ROK Corps, operating on the general direction of Yison-Andon, during the first days of the offensive encountered stiff resistance from the 2 ^nd KPA Group Army which fought them for four days on the forward line of defense. It was only by the end of the day on 19 September that the enemy succeeded in penetrating the defense thanks to the help from significant enemy aviation support and artillery fires, rupturing the with the 1 ^st and 8 ^th ROK Infantry Divisions pushing back the flanks of the 1 ^st and 13 ^th KPA Infantry Divisions and by 21 September they had reached the area of Guni, creating a threat to the withdrawal routes and rear area of the forces defending north of Yonchon.

On the auxiliary directions the enemy offensive went much slower. The IX US Corps, operating on the left flank of the strike force grouping, had advanced to the Naktong river by the end of the day on 21 September and forced a crossing with one regiment in the area of Yul’chili. The I ROK Corps, bringing units from the 1^st, 2^nd and 5^th ROK Infantry Divisions north of Phohan, could take the village only at the end of the day on 21 September.

For that reason, and in spite of the tremendous superiority in forces and means and absolute air and sea superiority, the UN had trouble penetrating the defenses of the KPA and over six days of combat only penetrated as little as 20 kilometers in some areas.

After rupturing the KPA defenses the temporary tactical group began to rapidly move along its primary routes of advance, striving to not let the retreating KPA forces get away and set up a defense along river barriers and advantageous natural lines.

By 21 September, the KPA forces, having taken exceptionally heavy losses, especially with artillery and tanks with a commensurate loss of communications between units and formations due to the continuous operations of enemy aviation against their lines of communication, communications nodes, and command posts, retreated to the line of Ginyei, Yul’cili, Namgedon,Gun’I, Mokuton, and north of Phohan.

As a result of the naval landing at Inchon and the developments from the line of the Naktong River the offensive in Korea developed along two separate directions, which were some 200-250 kilometers from each other. The KPA forces were thus forced to fight in two separate areas of the country, which had an insufficiently developed network of roads connecting them and also found themselves under constant enemy air operations.

Under the situation that had been created the commander of the 2 ^nd KPA Group Army made a decision on 21 September to launch a counterstrike in the area of Gun’I with the goal of restoring the situation. In accordance with these missions it was proposed to make use of the available units of the 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions as well as to bring up the 17 ^th Mechanized Division from the reserve.

But ultimately the counterstrike was not launched. The units of the 13 ^th, 1 ^st and 8 ^th KPA Infantry Divisions, withdrawing under strikes by the enemy, took heavy losses and therefore were not able to be used for launching the counterstrike. The units of the 17 ^th Mechanized Division, which had assembled in the area of Andon, even back on 17 September had been attached to the forces of the Seoul group of forces by order of the High Command of the KPA.

Thus the commander of the 2 ^nd KPA Group Army’s attempt to assign the 17 ^th Mechanized Division to launch the counterstrike in the Gun’I area can only be clarified by the poorly organized communications which subsequently meant that the commander could not carry out the orders of the High Command of the KPA.

The situation in the Seoul area got worse day by day. The forces were continuously in combat on this direction with all of the forces of the naval landing, who overcoming resistance from broken units and subunits of the KPA, got to the Han River on 21 September and prepared to force the river on a broad front.

From 21 September onward a terrible battle broke out on all directions and for the most part was fought along the roads. The UN forces, having a significant superiority in forces and assets and absolute air superiority, had moved 20-40 kilometers in the direction of Taegu in the five days after the landing and by the end of the day on 25 September had moved to a front of Chinju, Hyonchon, Kimchong, Hamchan, Andon, and Yondok. The forward detachment of the 1 ^st US Cavalry Division was fighting for Poyin.

On the Seoul direction the enemy had taken a bridgehead on the Han River northwest of Seoul . During 21-22 September they had repeatedly attempted to take Seoul , launching strikes from the northwest. The KPA forces, in repulsing these attacks, destroyed seven tanks and forced the enemy to retreat to their starting positions. On 23 September, after a powerful air and artillery bombardment and with the support of a large number of tanks, enemy infantry again went on the offensive, launching strikes simultaneously from the northwest and west.

In a destructive and tough battle the KPA forces destroyed 17 tanks, but they were not able to stop the enemy. The enemy, having significant superiority in troops and especially combat technology, broke into the city. A terrible street battle broke out.

Part of the forces of the 7 ^th US Infantry Division, which had entered combat back on 18 September, advanced on Suwon . In the area of Suwon at this time the defenders consisted of subunits of the 70 ^th Independent KPA Infantry Regiment. The lead subunits of the 1 ^st KPA Tank Brigade entered into combat on this direction on 23 September. In the resulting battle the enemy destroyed eight of their tanks, and overcoming stiff opposition put up by the remnants of the 70 ^th Regiment and the 1 ^st Tank Brigade, began to slowly move to the south. By the end of the day on 25 September the enemy had taken Suwon , and continuing the offensive in a southerly direction, joined up south of Usan on 27 September with the lead units of the 1 ^st US Cavalry Division advancing from the area of Taegu . These actions completed the operational encirclement of the forces of the 1 ^st KPA Group Army in the southern part of Korea .

Over the course of ten days (16-25 September) the American and South Korean forces, advancing from the Pusan bridgehead, moved from 30 to 60 kilometers (average speed of the offensive – 3-6 kilometers per day). On the Seoul direction the units of the naval landing at the same time were only able to move 25-30 kilometers (3 kilometers per day.)

The High Command of the KPA, assessing that the enemy with his operations on the Taejon direction could ultimately shatter the front, separate the formations of the 1 ^st KPA Group Army from their supply bases and destroy them, made the decision on 25 September to withdraw the forces of this group to the 38 ^th Parallel in the general area of Taejon and Seoul.

Being covered by a rear guard using engineer obstacles, the units and formations of the 1 ^st KPA Group Army had to subsequently retreat to the line Chyonan-Wonju.

With the goal of providing for the retreat of the 1^st KPA Group Army the commander of the 2^nd KPA Group Army was ordered to hold the line Kimchong-Sanju-Hamchan-Yechon-Andon-Yondok and not permit the enemy to break through this line. In this the primary attention was placed on covering the directions of Kimchong-Taejon; Hamchan-Munkyon and Andon-Yonju. Beside that, the commander of the 2^nd KPA Group Army had to bring up the reserve 12^th KPA Infantry Division and concentrate it in the area of Chekan to defend the subsequent line of Yanphen-Yonju.

Simultaneously the commander of the Seoul group of forces was ordered to concentrate the arriving reserves, take up a defense to the north, east and south of Seoul and interdict the movement of the enemy to the east and southeast directions.

But at the same time the measures ordered here did not consider the influence of the course of events. The command and control of the forces from the frontal staff and group army headquarters was disrupted. The KPA forces withdrew to the north in disfunctional groups, only putting up stiff resistance in isolated directions. Communications with the 1 ^st KPA Group Army was also totally disrupted.

On 26 September units of the 8 ^th ROK Infantry Division forced the Naktong River west of Andon and moved to the approaches to Yechon. Two days of hard combat then followed for the city. The subunits of the 1 ^st KPA Infantry Division withdrew from here during the night of 29 September under overwhelmingly superior enemy forces, but under constant bombardment by enemy aviation they were also forced to leave Yechon. The forces of the 2 ^nd KPA Group Army on all fronts began to retreat to the north towards the 38 ^th Parallel.

The size of a KPA infantry division by this time was only about 20% of its normal tabular strength. In infantry regiments operating at the front there were only 100-200 officers and men remaining, nearly totally without weapons, artillery and tanks. The troops just did not have anything that they needed for combat.

Under such a difficult situation the High Command of the KPA made the decision to withdraw all forces to the 38 ^th Parallel. With this goal in mind the forces of the Seoul group of forces were ordered to halt the offensive of the enemy along the front Konsonri-Yidenpu-Yootiri-Kansenri and by 5 October support the retreat of the 2 ^nd KPA Group Army to previously prepared defensive lines along the 38 ^th Parallel.

By the end of September the primary events developed along the Pyongyang , Chorwon and Wonsan directions.

Beginning on the morning of 29 September, after a heavy air and artillery bombardment units of the 1^st Marine Division, the 1^st US Cavalry Division, and the 8^th ROK Infantry Division attacked the KPA forces in the area of Yidenpu along the Pyongyang direction. Units of the Seoul group of forces stopped the enemy offensive and for five days turned back their mightiest attacks. It was only at the end of the day on 5 October that UN forces, bringing up additional forces, and backed by artillery, tanks and massive air strikes (using groups of 20-30 aircraft, averaging 2,500 sorties per day) that they reached the 38^th Parallel with great difficulty on the front near Kaysan and south of Chandong.

Along the Chorwon and Wonsan directions the I and II ROK Corps units continued to advance. They overcame weak resistance from shattered and isolated units of the 2 ^nd KPA Group Army that was retreating to the north, and by 8 October these corps had taken Indae and were fighting for Simpori, Hwachen, and Yangu. Isolated subunits from the 3 ^rd ROK Infantry Division succeeded in reaching Koje. The Singman Rhee forces met stiff resistance from the subunits of the 24 ^th KPA Marine Brigade that were defending along the coast.

For that reason, the enemy offensive from Taegu had continued for 23 days. During this time they had moved 240-300 kilometers and cut off the eastern sector of the front along the 38 ^th Parallel. The average daily speed of the advance was no more than 10-13 kilometers per day.

South Korean and American forces, in spite of their absolute air and sea superiority, were only able to take the port and city of Inchon after a three day battle and on the 15 ^th day of the offensive took Seoul . By the 24 ^th day units of the naval landing had moved 100 kilometers, which amounted to an average daily speed of movement of four kilometers per day. On some days total movement was no more than two or three kilometers.

The arrival of American and South Korean forces on the 38 ^th Parallel on 8 October, coming into the areas of Hiksiakni and north of that area, created an exceptionally difficult situation for the DPRK. As it was now obvious that the offensive could not be stopped, the High Command of the KPA was forced to send isolated, even poorly trained and poorly armed subunits into the areas being threatened.

2. Continuation of the Offensive of the UN and South Korean Forces to the North from the 38^th Parallel (11-24 October 1950)

After the arrival of the UN forces on the 38 ^th Parallel, the American command made the decision to conduct a new offensive operation with the goal of finally destroying the remnants of the KPA and occupying all of North Korea .

The overall concept of the operation included attiring KPA forces and the destruction of their units by means of simultaneously launching two strikes from two directions against Pyongyang : one from the area north of Seoul and the other from Wonsan . The offensive of the ground forces had to be carried out simultaneously with an air landing, which was proposed to drop in the area of Sukchen and Sunchon. After taking Pyongyang the forces were proposed to move to the north with the goal of quickly reaching the border of the Peoples Republic of China and the Soviet Union .

The main strike was to be launched on the western sector of the front along the lone Kaysen-Mansekwoli with the forces of three corps, staggered in two echelons.

The mission of these forces included breaking through the defenses by KPA formations along the line Sinsenri-Goniri, destroy the forces of the Seoul group of forces, and developing that success in a northwesterly direction, combine with the air and naval landing forces to take Pyongyang .

The second strike would be launched by X US Corps which was to be moved from Inchon and Pusan to Wonsan by sea. The mission of this corps was to take the ports of Hamhung and Wonsan , develop the offensive to the west with the goal of cutting off the routes of retreat of the KPA force grouping then operating in the areas of Chorwon, Hwachen and Wonsan to the north, and then join with the main force grouping to take Pyongyang .

The air landing (the 187 ^th RCT), which was proposed to be dropped into the areas of Sukchen and Sunchon, had to move to cut all routes moving from Pyongyang to the north in order to prevent the withdrawal of KPA forces from Pyongyang.

The I ROK Corps was designated to move along the eastern coast of Korea in another offensive.

The advance by these forces would be supported by air power from the USAF and US Naval forces.

The High Command of the KPA, having pulled the remnants of its forces back to the 38 ^th Parallel, made every effort in order to prevent the enemy moving north of that line. Together with this, the remnants of other KPA forces remaining in the enemy’s rear areas turned to partisan operations.

In the rear area of the country efforts were increased to form new formations and units to replace the divisions of the 2 ^nd KPA Group Army using hastily trained officers in order to create a new army.

Beside that, the High Command of the KPA planned to create defensive lines in the depths of the rear area, which would be manned by forces retreating from the front and reinforced by the reserves moved forward from the depths, which would resist the American forces.

The first defensive line was to be established about 160 kilometers north of the 38^th Parallel, along the front of Sukchen-Kowan and the second one at 240 kilometers along the right bank of the Chongchon River to Hichen and further to the east to Honchon.

Preparations for the UN forces to carry out the offensive north of the 38 ^th Parallel would begin during the final stage of the first operation.

With the goal of creating a strike force grouping, the Americans reorganized their forces and transferred new units and formations to Korea .

To reinforce the UN forces at the end of September and the beginning of October the 65 ^th RCT arrived in the Pusan area as well as the 50 ^th, 76 ^th and 78 ^th Independent AAA Battalions, the 17 ^th and 65 ^th Field Artillery Battalions, as well as the Thai independent infantry regiment of 2,000 men and officers and two independent battalions of Australian and Filipino troops, each of 1,000 men. Units of the 3 ^rd US Infantry Division also began to arrive. Beside that, the British sent three battalions of the 29 ^th Independent Infantry Brigade, the 7 ^th Armoured Regiment, artillery and engineer units with an overall total of 10,000 men to Korea .

The South Korean forces now included the newly reformed and replace 7 ^th ROK Infantry Division, the new 5 ^th and 11 ^th ROK Infantry Divisions, each with 12,000 men and officers. The strength of their remaining divisions was also brought back up to between 11 and 12, 000 men.

By 11 October, the American and South Korean forces occupied the following positions:

The I US Corps, with the 1 ^st US Cavalry Division and 24 ^th US Infantry Divisions, the 1 ^st ROK Infantry Division, and the 27 ^th British Infantry Brigade, had taken up its starting positions in the area of Kaysen to Hill 675;

The II ROK Corps was deployed in front from Hill 675 to Yangu, with its primary forces (the 8 ^th and 7 ^th ROK Infantry Divisions) in the sector of Hill 675 to Chokmokni, ready to advance in a northwestern direction to take Pyongyang from the east. The 6 ^th ROK Infantry Division of this corps, with the mission to advance with a front from Chokmokni to Yangu was to cover the junction of the II ROK Corps with I ROK Corps. The latter would advance along the east coast of Korea .

The second echelon of the main force grouping of UN forces consisted of the formations of the IX US Corps with the following dispositions: the 2 ^nd US Infantry Division was in Suwon . The 25 ^th US Infantry Division was in Taejon and Poyinye and the 11 ^th ROK Infantry Division was in Taegu .

Beside that, in the southern part of Korea were the 5 ^th ROK and 3 ^rd US Infantry Divisions, which composed the reserve of the command of the South Korean forces.

The X US Corps (1 ^st Marine Division and the 7 ^th US Infantry Division) were concentrated in the Inchon and Pusan areas for replacements and for transfer by sea to Wonson, and the 187 ^thRCT was located at Kimpo.

For that reason, by the start of the offensive operation in October 1950 the Singman Rhee regime in South Korea had concentrated 15 infantry divisions, one infantry brigade, five independent infantry regiments, nine independent infantry battalions, four independent tank battalions, and a significant number of artillery from the reserve of the high command. The overall total of these forces exceeded 200,000 men. Along the direction of the main strike were eight infantry divisions and one infantry brigade with an overall total of 120,000 men and officers, as well as 500 tanks. By this time the American command had, with the addition of naval aviation, 1,415 combat aircraft (170 heavy bombers, 180 medium bombers, 975 fighters and 90 reconnaissance aircraft.)

The combined naval fleet of the UN forces now consisted of one battleship, 11 aircraft carriers, 10 cruisers, 48 destroyers, 13 service vessels, 45 mine sweepers, four submarines, more than 100 transports, auxiliary vessels, and other vessels. The Navy had to support the transfer of X US Corps to Wonsan and provide support with naval gunfire and air power to the forces along the coastal strip.

The preparations by the KPA to repulse this enemy offensive took place under extremely difficult conditions. On the 38 ^th Parallel the KPA forces were the most organized, even after taking heavy losses, withdrew the Seoul group of forces of up to two infantry divisions and the remnants of three infantry divisions of the 2 ^nd KPA Group Army.

Subsequently on the Wonsan front things were relatively wide open. The High Command of the KPA was forced to withdraw on this direction to the rear area all reserve units and all units which were still not completely done forming. Thus, the introduction of the 18 ^th KPA Infantry Division and the 25 ^th and 27 ^th KPA Fortified Region Brigades saw them all virtually without weapons or equipment. In early October part of the forces of the 19 ^th KPA Infantry Divisions, also equally as poorly equipped, was sent from Pyongyang to the 38 ^th Parallel, and the 92 ^nd KPA Reserve Regiment was sent from Chorwon to Simpori to strengthen the remnants of the 1 ^st and 12 ^th KPA Infantry Divisions from the 2 ^nd KPA Group Army, which were withdrawn into that area. All of these forces, poorly trained and with insufficient weaponry, entered into combat with significantly superior forces of the enemy and with difficulty held the enemy on the 38 ^th Parallel.

For that reason, in early October the KPA forces located along the 38 ^th Parallel, which ran for some 200 kilometers, included the 97 ^th KPA Reserve Regiment, border guards and police regiments, the infantry and tank regiments of the 19 ^th KPA Infantry Division, the 26 ^th and 27 ^th Fortified Area Brigades, the 92 ^nd Reserve Regiment, and remnants of the 1 ^st, 3 ^rd, 12 ^th and 9 ^th KPA Infantry Divisions of the 2 ^nd KPA Group Army.

The nearby reserves were located in Sannen (the 25^th Fortified Area Brigade), Chorwon (units of the 31^st KPA Infantry Division), and Chipori (remnants of the 18^th KPA Infantry Division and the 33^rd Independent KPA Infantry Regiment). In Namchyon, units of the 19^th KPA Infantry Division were assembled, and in the area of Pyongkan was the unformed 32^nd KPA Infantry Brigade.

The seacoasts of the country were protected by three brigades of marines, each of which consisted of six battalions. The 25 ^th KPA Marine Brigade, with one battalion of artillery, covered the west coast along the 300 kilometer front from Nampo to Ongdin. The Seysin and 24 ^th KPA Marine Brigade (the latter reinforced with an artillery regiment) covered the ports on the east coast: the former covered Yuki, Iuon and the latter covered Simpo and Wonsan . The overall front covered by these brigades was over 700 kilometers. The marine battalions and artillery batteries were allocated to individual garrisons in the ports and coastal settlements, e.g. in the most probable places that the enemy would make a naval landing.

In the areas of Chehnju, Nampo, Wonsan , and Nanam were the forming 43 ^rd, 46 ^th, 42 ^nd, and 41 ^st KPA Infantry Divisions, the 41 ^st and 45 ^th Tank Regiments, and other units and subunits, and in the area of Pyongyang were the reforming 17 ^th Mechanized and 105 ^th Tank Divisions. The numerical strength of each one of the forming divisions did not exceed 10,000 men, and each regiment was no more than 3,000 strong. Replacement was bogged down by the fact that the KPA was completely without aviation or naval forces.

The defensive lines by this time were still not prepared and could not be used by troops.

The overall correlation of forces and means across the entire front by 10 October 1950 was as shown in Table 5.

Item

KPA Forces

US and ROK Forces

Ratio

People

Tanks and SP Guns

Guns and Mortars

Aircraft

93,498

67/169

203,888

800

552/1,760*

1,415

1:2.2

1:12

1.9.7

Absolute enemy air supremacy

* - Note: the number of guns is in front of the slash, the number of mortars after

Table 6 shows the correlation of forces and means on the direction of the main strike on the Kaysen-Changdong front.

Item

KPA Forces

US and ROK Forces

Ratio

People

Tanks and SP Guns

Guns and Mortars

Aircraft

Around 30,000

About 40

24/143

120,000

Around 500

492/1,400

1,415

1:4

1:12.5

1:11.5

Absolute enemy air supremacy

By the start of offensive operations American aviation had destroyed 18 bridges in North Korea , as well as 11 railway stations and yards and two tunnels, thus paralyzing movement on the DPRK railways.

The enemy offensive began on the morning of 11 October after a mighty artillery and aerial bombardment. The KPA forces were attacked on the front from the bed of the Yaesong River to Chandon.

Units of the 19 ^th KPA Infantry Division and 27 ^th Fortified Area Brigade, putting up stiff resistance, turned back all attempts by the enemy to break through to Kimchenu. The American command, in order to rupture the KPA defenses on the Kimchenu direction, were forced to commit the forces of the 1 ^st US Cavalry and 7 ^th US Infantry Divisions on the first day of the battle, as well as part of the forces of the 24 ^th US Infantry Division.

Along the Yenan direction the enemy committed the 27 ^th British Infantry Brigade which began to tear apart the subunits of the 97 ^th Reserve Regiment on the western direction. The KPA command was forced to commit the units of the forming 43 ^rd KPA Infantry Division on this direction.

Defending along the Chorwon direction, the subunits of the 26 ^th Fortified Area Brigade and the 92 ^nd Reserve Regiment were not able to withstand the pounding by enemy air strikes, and were thus forced to withdraw to the mountains, opening up the direction to Ichen-Men and Pyongkan.

The poorly-equipped 31 ^st KPA Infantry Division (in the Chorwon area), the 25 ^th Fortified Area Brigade (in the Sannen area), and the subunits of the 32 ^nd KPA Infantry Brigade (in the Pyongkan area) were likewise unable to put up any meaningful resistance.

Units of the 8 ^th and 7 ^th ROK Infantry Divisions, seizing Pyongkan, continued the offensive and, deploying their main body towards Ichen-Men, had reached the Pyogannhyon River by the end of the day on 12 October.

The 3 ^rd ROK and Capital Infantry Divisions, advancing along the east coast, took Anbyen on 11 October as well as Sayim and continued to develop the offensive in the direction of Wonsan . The city and port of Wonson were defended by three infantry battalions, engineer and sapper battalions from the 24 ^th KPA Marine Brigade, the 96 ^th Reserve Regiment, and the 41 ^st Tank Regiment (with 10 tanks.) All of these subunits had a tremendous shortage of personnel and equipment. After the battle, during which they took heavy losses in personnel and military technology, these forces left Wonson on 12 October.

Consequently, even by 12 October the KPA forces found themselves in a very difficult situation. The enemy had ruptured the defense along the Chorwon direction, moved his forces up to 50 kilometers deep into the north, and taken Wonsan , all of which created a real threat to Pyongyang . The High Command of the KPA, with the goal of easing the situation for its forces operating along the Kimchenu-Namchyon direction, took a number of immediate measures to strengthen the defense of the eastern sector of the front. Units of the 42 ^nd KPA Infantry Division were sent in towards the Wonsan sector of the front, and units of the 43 ^rd KPA Infantry Division were sent towards Yenan. Groups and detachments of signals troops, sappers and other specialized forces were also hastily created.

By 19 October two fronts had been designated. The 1^st Front consisted of those formations and units operating on the Pyongyang direction. The 2^nd Front was organized with those forces covering the eastern coast in the border areas of Munchen and Pukchanni.[5]

The American and South Korean forces, continuing to advance to the north and northwest directions, had reached the Nam River by 15 October, forced it in the area of Simpen (80 kilometesrs southeast of Pyongyang), and taken the cities of Yenan, Namchyong, Simpen, Tonyan and Chowon.

Following the subsequent withdrawal of KPA units on the Pyongyang direction, the American and South Korean forces had moved to the southern and eastern outskirts of Pyongyang by 19 October and were gathering the forces of two corps for combat for the city.

The tough battle for Pyongyang lasted two days. It was only by 20 October that the enemy succeeded in taking Pyongyang . The outcome of the battles for the city had a strong influence on the airborne assault, the main body of which the enemy had dropped on the morning of 20 October in the Sukchen-Sunchon areas.

The airborne assault was preceded by a ten-day-long intensive bombardment of the area that was proposed for the drop zones. An hour and a half prior to the drop close air support prepared the area for them. The airborne assault was dropped 45 kilometers from the front lines, where there were absolutely no KPA forces, which meant that the enemy could take the cities of Sukchen and Sunchon without resistance and thus cut off the routes of retreat from Pyongyang . [6]

With the goal of preventing movement by the enemy north of the Chongchon River, the KPA command decided to take up the defense using forces of one infantry regiment from the 47 ^th KPA Infantry Division and the 17 ^th Mechanized Division on the north bank of the river in the vicinity of Ochenpuri, north of Kechyon, and to not permit movement of the airborne assault in a northwesterly direction. Two infantry regiments from this division had to take up the defense on the front of Toksondong-Sansondong and cover the concentration of forces of the Chinese Peoples’ Volunteers (CPV) in the area of Kusong and Bugdin. One infantry and one tank regiments were deployed along the line from Dibandong to Chyungodong to support the crossing of the CPV in the area of Sinuiju .

Units of the 46^th KPA Infantry Division, taking up the defense in the vicinity of Hanchen and Yanpori, were ordere to destroy the enemy airborne assault. But at the same time the division could not carry out this mission and on 21-21 October the airborne assault joined up with units of the 1^st US Cavalry Division in the Sukchen and Sunchon area as well as with units of the South Korean forces advancing from Pyongyang . Units of the 46^th KPA Infantry Division, reeling under strikes by the enemy from the north and south, were forced to retreat in a northwesterly direction.

Forces of the I US Corps, together with the airborne assault, developed the offensive and moved along the railways and highways to Pyongyan, Anju, and by 25 October had taken Anju and then attempted to force the Chongchon River from the march.

The II ROK Corps also continued to advance along the roads in the direction of Tokchyon-Hichen and on 25 October took the cities of Uznan, Sanwontong, Udan, and Hichen. Isolated elements of the 7 ^th Regiment of the 6 ^th ROK Infantry Division succeeded on 26 October of moving to the Yalu River on the border of Korea and China and took the city of Chesan .

Attempts by the UN forces to force the Chongchon River in the area of Anju and further develop the offensive towards Sinuiju and Bugdin were cut off by a stiff resistance from the 105 ^th Tank Division and 17 ^th Mechanized Division, an infantry regiment from the 47 ^th KPA Infantry Division, and remnants of units from the 19 ^th and 45 ^th KPA Infantry Divisions of the 1 ^st KPA Front.

The KPA forces received a significant amount of help in holding the defensive line of Namodong, Uznan, Sanwontong, and Udan from leading units of the CPV, which were concentrating in the northwestern part of Korea . They launched a number of heavy counterattacks, inflicted serious losses on units of the 6 ^th ROK Infantry Division, and halted enemy movement on this direction.

But at the same time the situation in Korea remained stressful. Between 20-25 October the American command carried out a naval landing at Wonsan with units of the 1 ^st Marine Division and provided for the further movement of the Capital and 3 ^rd ROK Infantry Divisions. By 25 October units of these divisions, not meeting any sort of resistance, had taken Kochedong, Tohinri, Pukchyon, Kunsong and were hurrying towards the northern border of the DPRK.

Together with the arrival of the CPV in Korea , the KPA began to put up much stiffer resistance in the western sector of the front. The American command was forced to bring up the 2 ^nd US Infantry Division from Pyongyang to Anju and take other measures to reinforce operational forces. By 25 October the 86 ^th US Tank Battalion had arrived at the front. On 18 October the port of Pusan began to offload subunits of the Turkish brigade, which then headed towards the front through Taegu . Starting on 26 October the 7 ^th US Infantry Division began to arrive in the area of Hamhin.

A significant amount of help to KPA forces during the course of operations north of the 38^th Parallel was provided by partisans. The KPA command paid a great deal of attention to the partisan movement. The forces which were operating in the enemy’s rear area were organized into the 2^nd Partisan Army. In October 1950, partisan units operating in the DPRK amounted to around 40,000 personnel.

The most active partisan activity in this time frame was in the area north of Wonsan and northwest of Taegu .

Thus, subunits of the 10 ^th KPA Infantry Division, numbering around 7,000 men and operating along the road from Kumhwa to Yidenpu, liberated the cities of Kumhwa, Hwachen and blockaded the enemy garrison in Chungchen. A detachment of 1,500 men from the 9 ^th KPA Infantry Division and a detachment of 1,000 men from the 3 ^rd KPA Infantry Division were based in the Koksan area.

Major road and rail junctions, such as those at Ichon, Chyongan, Taejon , Chongju, Kwangju , Taegu and others were continuously struck by partisans.

The American command, concerned at the growth of partisan activity, was forced to send complete units, formations and even aviation into action against them.

The battle with partisans in the areas listed above required units of the 5 ^th , 9 ^th and 11 ^th ROK Infantry Divisions, the Turkish brigade, and other elements.

Between 19 and 25 October, operations against partisans operating in the area south of Wonsan required the participation of the entire 2 ^nd ROK Infantry Division, and in the Koje area, units of the 3 ^rd ROK Infantry Division and the 1 ^st Marine Division.

The American command carefully studied the methods and tactics of the partisan detachments, placed entire areas under siege, and made wide use of Japanese officers who had taken part in combating partisans during the Sino-Japanese war.

The advance of UN forces from the 38 ^th Parallel lasted 15 days (11-25 October). During this time they moved to a depth of 250-280 kilometers and moved to the Chongchon River in the west and to the northern regions of the DPRK in the east. The average speed of movement was 16-18 kilometers per day.

3. Overall Results and Characteristic Picture of Combat Operations During the Second Stage

Overall Results. Combat operations by KPA forces in the second stage of the war took place under extremely difficult conditions. The difficult of these operations was first and foremost determined by the inequality of the forces: the extremely insufficient number of weapons and forces in the KPA and the huge numerical superiority of UN forces, as well as to the limits of equipment with various types of combat technology.

The KPA forces took significant losses in troops and especially combat technology from enemy aviation and artillery, and were forced to retreat to the northern regions of the country.

Due to their strength the UN forces were able to carry out two sequential offensive operations and succeed in moving deep within the territory of the DPRK.

Characteristic picture of operations by the Korean Peoples Army. The retreating forces which were in direct contact with the enemy, who had overwhelming superiority in numbers of forces and means, found this one of the most difficult and hardest aspects of combat operations.

It demanded that the forces, headquarters and commanders at all levels continuously study the changing enemy and his force groupings, make an all around assessment of the nature of operations by his forces, maintain solid command and control, strict discipline, and high alertness.

But at the same time, as shown by combat operations, the KPA forces were not able to carry out these demands to the fullest measure, as due to the continuous operations of enemy aviation it led to the loss of command and control over the troops and worsening of the situation at the front.

The loss of command and control during this period exacerbated some of the ongoing confusion in the headquarters of the group armies and the fronts. Only decisive interference by the High Command of the KPA helped organize stopping the enemy in the Seoul area. But at the same time, in spite of a number of measures taken to strengthen the defense of Seoul and improve the situation at the front, individual important dispositions required of the commanders of the group armies and the division commanders were not made. They did not carry out the order to break off combat along the Naktong River in a given time frame and withdraw the units of the 1 ^st and 9 ^th KPA Infantry Divisions to the Seoul area, as well as to move the units of the 17 ^th Mechanized Division into the Suwon area.

The loss of command and control and the thoughtlessness of responsible individuals to establish communications with their subordinate forces led to even great disorganization during the retreat.

As for the number of commensurate shortcomings it follows to lay out the lack of prepared defensive lines in the rear area of the KPA, as well as strong points and nodes of resistance. In the entire territory from the Naktong River to the northern borders of the DPRK there was not one single defensive line established where the withdrawing forces could dig in and show resistance to the enemy.

The Naktong River line which was reached by the KPA forces was not strengthened from an engineer standpoint. There were no trenches, liaison paths, cover and dugouts, engineer obstacles, to say nothing of deeply echeloned engineer works. Among the forces it would have been useful to set up a simple defense using all of the superiority of the terrain and major water obstacles.

It was only during the defense of Seoul that the forces, taking up a defensive line on the left bank of the Han River northwest of Seoul , were able to hold up the offensive by the naval landing for a long period of time.

Per the decision of the government of the DPRK engineer units from the fronts and local residents were supposed to construct two defensive lines north of the 38 ^th Parallel. But at the same time the work on these lines was not carried out in September or October. The positions along the second defensive line were only prepared on the northwestern bank of the Chongchon River in the Namodong-Hichen sector when the units and subunits of the KPA forces retreated there from the 38 ^th Parallel.

Things were even worse with the organization of an anti-landing coastal defense, as well as defense against enemy airborne assault. All of this simplified the landing of UN forces with a naval landing at Inchon , as well as the paradrop north of Pyongyang .

One of the shortcomings of operations by KPA forces was their poor combat support. Reconnaissance was very poor due to a lack of ground, air and sea assets. The presence of the American command, their force grouping and the makeup of the UN forces was frequently never detected by the KPA command. Perhaps this led to the fact that on the direction of the main strike northwest from Taegu the defense was more weakly organized, and in the area of the probable landing zones ( Inchon , Sukchon) they were insufficiently protected by the reserves.

Commensurate shortcomings were also found in the organization of antitank defenses. As opposed to the first stage of the war when the organization of antitank defenses did not receive proper attention due to a lack of enemy tanks and SP guns, during the second stage of the war there were practically no organized antitank measures, not just as a consequence of a shortage of antitank artillery and engineer means in the KPA forces, but due to an underestimation of the situation.

During the withdrawal there were huge gaps between units and formations, but at the same time commanders did not always pay sufficient attention to the questions of flank and seam support.

Characteristic picture and operations by UN and South Korean army forces. In accordance with their offensive, UN and South Korean army forces had one common goal – the destruction of the KPA and an advance to the northern border of the DPRK as the ultimate development of combat operations.

The strike by UN forces from the Naktong River line to the north and northwest directions hit right on the seam of the 1^st and 2^nd KPA Group Armies, as it was the weakest spot in their defenses. The advancing forces had the ability to make use of a widely developed network of roads and pick the shortest possible distance between them and the naval landing which was advancing from Inchon .

During the offensive the American and South Korean forces north of the 38 ^th Parallel launched their main strike into the most densely manned force grouping of the KPA in the defense, and with their destruction it would rupture the entire defense north of the 38 ^th Parallel.

The naval landing at Inchon and the strikes against the flanks and rear of the KPA had a decisive influence on the entire subsequent outcome of events. This was possible as the naval landing was prepared far from the shores of Korea , primarily in the ports of Japan , and in areas where the KPA navy and aviation could not reach. The Inchon operation by UN armed forces decisively changed the course of the war. In the offensive north from the 38 ^th Parallel in October 1950 the situation created was such that another such naval landing was no longer required. In point of fact, the other naval landing was more of a transfer of forces by sea and landing on a coastline which had already been occupied by ground forces.

The main UN force grouping in the offensive from the Naktong River north consisted of seven infantry divisions and all of the reinforcing means from the reserve of the high command. Along a 70 kilometer front which constituted only 27% of the length of the entire front they concentrated nearly 70% of their infantry formations, artillery and tank assets.

The advance to the 38 ^th Parallel was planned for a depth of around 240 kilometers, and from the Inchon area a distance of 100 kilometers. The operation took 23-24 days. The speed of the offensive by the Singman Rhee forces reached 10-12 kilometers per day, but in the Inchon area the speed was only 3-4 kilometers per day. On individual days, due to intensive resistance from the KPA forces, the movement rate was as little as 2-3 kilometers per day.

The offensive of the UN forces north of the 38 ^th Parallel to a corresponding depth of 250 kilometers moved at a speed of 15-20 kilometers per day.

A number of differences were observed in the structure of forces north of the 38 ^th Parallel. If during the first operation all of the American and South Korean forces were deployed in a single echelon with only a small army reserve allocated (two independent infantry regiments) then during the second operation the army had the entire IX US Corps as their second echelon with three infantry divisions. Beside that, the combat order of the corps in the first echelon were likewise deeply echeloned.

This position, perhaps, can be clarified by the sufficient number of forces and means as well as the striving by the American command to retain sufficient forces for a continuous combat effort on the direction of the main strike with a goal of a rapid movement to the Yalu River on the border with the Peoples Republic of China .

Cooperation among the ground forces, airborne assault forces, aviation and naval forces was demonstrated by a series of simultaneous strikes by forces from the front, flanks and rear of the enemy with continuous support from numerous air and naval gunfire strikes.

The achievement of operational cooperation corresponded to a great degree with the lack of KPA naval and air forces, as well as sufficient numbers of artillery and especially antiaircraft artillery assets to organize a counter-landing and counter-air defense.

During the advance by American and South Korean forces from the Naktong River to the 38 ^th Parallel they were able to achieve cooperation with the naval landing landed days before in the Inchon area and operating for 12-13 days while cut off from the main body. The coordinated strikes from the front, flanks and rear with continuous aviation support, inflicting strikes against the troops, headquarters, lines of communication, and objects in the rear area, crushed the front held by the KPA and even in the first days the enemy offensive forced them to withdraw to the 38 ^th Parallel.

Advancing from the 38 ^th Parallel, the American command dropped an airborne assault north of Pyongyang . The assault, operating for a period of two days in the rear of the KPA and 45 kilometers from the front lines, cut off all lines of retreat and evacuation by the KPA to the north and by itself simplified the battle for Pyongyang .

During the offensive the American and South Korean forces operated on a broad front on independent directions, each a significant distance from each other and for the most part following the roads.

The offensive was carried out by what are termed regimental groups, which strive to capture road junctions and, in spite of any remaining enemy forces resisting in their rear area, move forward as fast as possible. The makeup of a regiment group depended upon the situation and varied, but frequently they consisted of an infantry regiment, one battalion of field artillery, an antiaircraft artillery battery, an engineer company and tanks. Along with the regiment groups wide use was made of temporary tactical groups, which corresponding carried out the role of forward detachments. The makeup of these groups varied from an infantry battalion to a regiment, reinforced by artillery and tanks.

During the second stage of the war the American command began to make wide use of tanks. Tank subunits in infantry regiments and divisions were used for the most part in direct infantry support roles. Frequently the subunits of a tank battalion operated with the forward units or subunits carrying out the role of forward detachment. Tanks were not allocated to carry out separate missions. The largest single tank units taking part in combat operations were tank battalions.

In isolated cases such as, for example, when advancing from the line of the Naktong River to the area of the 38^th Parallel, as well as at Inchon and Seoul , infantry divisions advancing on the direction of the main strike received independent tank battalions from the reserve of the high command along with their organic tank assets. The offensive of divisions in this case could be supported by a group of 130-150 tanks. But at the same time, in spite of that increase in tanks operating along a broad front, they were, as is correct, only working together with infantry.

In the period when temporary tactical groups were being used they also received tanks, where they had the mission of tracking the withdrawing KPA forces, and taking and holding important lines and objectives until the arrival of the main body, as well as joining up with the air and naval landings.

In regard to artillery, there was nothing new in regard to the experience of the Great Patriotic War in their use. The advance of American and South Korean forces normally began with an artillery and air bombardment, which lasted 40-60 minutes and included one or two powerful fire strikes. Artillery fires were characterized by the organization and conduct of fire from concealed positions by tanks and self-propelled guns. Along the direction of the main strike when advancing north from Taegu, in the battles for Seoul and in the area of the 38 ^th Parallel the artillery density approached 100 guns and mortars per kilometer of front. Along secondary sectors the density was no more than 40 guns and mortars per kilometer. During the course of the offensive artillery support and accompaniment corresponded to the method of subsequent concentrations of fire on the most important objectives and targets interfering with the advance of the forces.

In cases where artillery and air support was needed again for the offensive, this time it took no more than 30 minutes and only after repeated lack of success by air and artillery strikes would working over KPA positions receive several hours or even days worth of strikes. This took place in Inchon and Seoul . After that, when KPA subunits rebuffed the first attempt by the enemy to get his naval landing ashore, on 14 September the American command launched massive air strikes and naval shore bombardment into the port and city of Inchon. In the area of Seoul , after an unsuccessful attempt to force the Han River and take the city from the march the enemy launched a three day bombardment and shelled the city.

For firing on ground targets, as a consequence of a lack of KPA aviation the American command made wide use of antiaircraft artillery. The antiaircraft guns were included in temporary tactical groups and reconnaissance groups, and on occasion in the advance guard as well as in front of the infantry. The antiaircraft guns were used in direct fire mode and at ranges of 500-600 meters to support and accompany tanks by means of suppressing and destroying antitank means, shattering obstacles and covering the troops during movement and changing positions.

Engineer support to combat operations of the UN forces for the most part consisted of hasty establishment of engineer defensive works along captured lines, organization of crossing points at water obstacles, the construction and maintenance of runways and field airfields; work on mining, repairing roads, and providing the troops with engineer items. Engineer preparation of terrain at the starting line included mine clearing, hasty artillery and mortar positions, and cover for command posts and personnel.

Forcing water obstacles was carried out, as is correct, from the march and frequently took place at simple crossing sites. In those situations where KPA forces resisted at the water crossing points, the forced crossing was preceded by powerful air and artillery strikes against the KPA defensive positions.

The forced crossing of the Naktong River in September 1950 was carried out on a broad front with absolute air supremacy by UN forces and powerful artillery support and was more like a simple crossing to the opposite bank. Analogous operations subsequently followed with the crossing of the Kim River , Kimpo River and others.

Together with that, the offensive by the Americans basically followed the roads, and repair of these roads and maintaining them in good order was given a great deal of attention both during the preparation for the offensive as well as during its conduct. But at the same time the Americans built no new roads, and it limited them to only moving in small convoys and accessible routes to artillery firing positions. During the offensive each infantry division received no more than two roads upon which to conduct their movement.

A great deal of attention was likewise paid to building the runways (VPP) and construction of basic airfields directly on and in adjacent sectors of the roads and in relatively flat sectors of terrain. Just between 29 September and 31 October the engineer battalion of the 24 ^th US Infantry Division constructed nine runways. On average they built one landing area or fitted out one airfield under conditions of assistance from the local population and South Korean forces every two to five days.

To support the offensive by the ground forces they made wide use of American aviation. Operating in groups of 20-30 aircraft, they made 1,200 to 1,500 sorties a day for the forces and 600-800 more into the rear area and against the lines of communication of the KPA, launching massive strikes against troops, headquarters, lines of communication and military and industrial objects in the DPRK.

Planned aviation preparation missions were carried out over a broad front over the course of 5-10 days from the start of the offensive and with the goal of supporting the landings of the naval landing at Inchon and the parachute drop of the airborne assault in October 1950 north of Pyongyang .

Unplanned aviation preparation missions lasted 1-3 hours prior to the offensive and were carried out at the same time as the artillery preparation for the attack.

The offensive operation and combat by American and South Korean forces during the second stage of the war in Korea showed a number of shortcomings in the operations of their units and formations. This was reflected in the slow speed of movement of the offensive by UN forces. During the course of the battles the lack of sufficient combat training of the enemy forces came out, as they had arrived in

Korea

as replacements with no thought of night operations or any concept of how to use the mountainous relief of the terrain. The combat order during the offensive was structured like that used on level terrain. The offensive was carried out on the entire front, but only during daylight. There was no thought given to making use of the mountains for necessary maneuver. The infantry could only operate with the immediate support of accompanying artillery, tanks and continuous aviation support.

By exclusively moving along the roads, it increased their vulnerability to attacks from the flanks or rear, and the pain of encirclement – there were such characteristic moments that happened to the UN forces during the second stage of the war.

[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] The overall question on preparing and conducting the naval landing at Inchon are addressed in Chapter 10.

[4] The 18^th KPA Infantry Division was formed based on the 18^th KPA Infantry Brigade.

[5] At the end of October a significant portion of the territory of the DPRK was occupied by the enemy, and therefore these frontal commands lost their significance and were disestablished.

[6] A more detailed account of airborne operations is provided in Chapter 11.