First and Second Battles of Wonju

The First and Second Battles of Wonju (Bataille de Wonju), also known as the Wonju Campaign or the Third Phase Campaign Eastern Sector, was a series of engagements between North Korean and United Nations (UN) forces during the Korean War. The battle took place from December 31, 1950 to January 20, 1951 around the South Korean town of Wonju. In coordination with the Chinese capture of Seoul on the western front, the North Korean People's Army attempted to capture Wonju in an effort to destabilize the UN defenses along the central and the eastern fronts.

After a joint Chinese and North Korean assault breached the UN defenses at Chuncheon on New Year's Eve of 1951, the North Korean V Corps attacked  the US X Corps at Wonju while the North Korean II Corps harassed US X Corps' rear by engaging in guerrilla warfare. In response, the US X Corps under the command of Major General Edward Almond managed to cripple the North Korean forces at Wonju, and the UN forces later carried out a number of anti-guerrilla operations against the North Korean infiltrators. In the aftermath of the battle, the North Korean forces on the central and the eastern fronts were decimated, allowing the UN front to be stabilized at the 37th parallel.

Background
After launching a surprise invasion of South Korea in June 1950, the North Korean People's Army (KPA) was shattered by the United Nations (UN) forces following the landing at Incheon in September 1950, with the remnants of the KPA fleeing northward while seeking sanctuaries in the mountainous region along the Sino-Korean border. The destruction of the KPA prompted China to intervene in the Korean War, and Chinese forces launched a series of surprise attacks against the UN forces near the border during November 1950. The resulting battles in the Ch'ongch'on River valley and at Chosin Reservoir forced the UN forces to retreat back to the 38th parallel by December 1950. On the eastern front, the US X Corps was trapped at the port of Hungnam near the Chosin Reservoir during the surprise Chinese offensive, and was forced to evacuate North Korea by sea on December 24, 1950. In its absence, the Republic of Korea (ROK) Army was forced to take over the defenses of the central and the eastern fronts along the 38th parallel, including the important road junction of Wonju located near the central front. The sudden defeat of the UN forces offered the decimated KPA a brief respite, and the shattered North Korean forces soon rebuilt their strength at the end of 1950.

In the aftermath of the Chinese successes, China's Chairman Mao Zedong immediately ordered another offensive against the UN forces on the urging of North Korean Premier Kim Il-sung. The offensive, dubbed the "Third Phase Campaign", was a border intrusion into South Korea that envisioned the total destruction of South Korean forces along the 38th parallel, and was aimed at pressuring the UN forces to withdraw from the Korean Peninsula. The western sector of the offensive was under the control of the Chinese People's Volunteer Army (PVA) 13th Army, and the 13th Army's action would later result in capture of Seoul on January 4. With the PVA 9th Army decimated at the Chosin Reservoir, however, the eastern sector of the offensive was handed over to the rehabilitated KPA, under the overall command of Lieutenant General Kim Ung and Commissar Pak Il-u. On December 23, 1950, General Walton Walker, commander of the US Eighth Army, died in a traffic accident, and Lieutenant General Matthew B. Ridgway assumed command of the Eighth Army on December 26, 1950.

Locations, terrain and weather
The battle's main focus was around a road dubbed "Route 29", a strategically important line of communication to the UN forces in central Korea. Wonju was a critical crossroad village on Route 29 which ran north to south and connects Chuncheon on the 38th parallel with Daegu on the Pusan Perimeter. Another road, which ran from the northwest, connected Route 29 and the South Korean capital of Seoul at Wonju. Between Chuncheon and Wonju stood the town of Hoengseong, and from Wonju to Daegu were a series of towns such as Chechon, Tanyang, Punggi and Andong. The entire road network was situated within the rough hilly terrains of the Taebaek Mountain Range. The fighting around Wonju occurred during some of the worst Korean winter conditions, with temperatures as low as -30 °F and snow as thick as 14 inch on the ground. Indeed the weather was so cold that metal on artillery pieces would crack, while water could take an hour-and-a-half to boil. At times the cold weather alone was enough to stall all military activities, while frostbite caused more casualties than combat during the course of the battle.

Forces and strategy
Just days before his death, Walker had tried to bolster the defences of the central and eastern sections of the 38th parallel by stretching the South Korean forces from Chuncheon to the Korean east coast. Following his instructions, the ROK III Corps was placed around Chuncheon while the ROK I Corps was deployed on the east coast. Meanwhile, the ROK II Corps, with its strength reduced to a single infantry division in the aftermath of the Ch'ongch'on River battle, filled the gap between the ROK I and III Corps. However with the absence of the US X Corps, the UN defenses on the central and eastern fronts were stretched thin, and there were gaps between the understrength South Korean units. Because the South Korean forces had suffered nearly 45,000 casualties by the end of 1950, most of their units were composed of raw recruits with little training, and out of the four South Korean divisions that defended Chuncheon, only one was deemed battle worthy. Taking advantage of the situation, the North Korean forces had been probing the South Korean lines since mid-December, while thousands of North Korean guerrillas harassed the UN rear area from their mountain hideouts. On December 27, 1950, the KPA II Corps managed to move behind the UN defenses by mauling the ROK 9th Infantry Division on the ROK I Corps' left flank at Hyon-ri. This development threatened to destabilize the entire UN eastern front.

In order to defend against the North Korean penetration, Ridgway immediately ordered the US X Corps to reinforce the South Korean defenses. However, with most of the US X Corps still assembling at Pusan, the only unit that was available in the Eighth Army's reserve was the US 2nd Infantry Division, which was still recovering from its earlier losses in the Ch'ongch'on River valley. On December 28, Ridgway ordered the US 2nd Infantry Division to defend Wonju while placing the division under US X Corps control. After the US 7th Infantry Division of the US X Corps finished reorganization on December 30, Ridgway ordered Major General Edward Almond, commander of the US X Corps, to develop Route 29 as its main supply route, and the 7th Infantry Division was subsequently tasked with defending it.

In coordination with the Chinese assaults against Seoul in the western sector of the Third Phase Campaign, the North Koreans deployed the KPA II, III and V Corps—an estimated total of 61,500 soldiers—against the UN forces on the central front. The North Korean plan was a frontal attack at Wonju by Major General Pang Ho San's KPA V Corps, while Major General Ch'oe Hyon's KPA II Corps would infiltrate the US X Corps rear as guerrillas and block Route 29. The aim of the offensive was to push the US X Corps back in concert with the Chinese attacks on Seoul, thereby isolating the South Korean forces in the Taebaek Mountains. As part of the Chinese attacks against Seoul, the Chinese 42nd and 66th Corps were deployed near Chuncheon in support of the KPA V Corps during the opening phase of the battle. Meanwhile the KPA III Corps would act as reinforcements for the KPA II and V Corps. However, like the South Koreans they were facing, the North Korean forces were also badly depleted and understrength. Although the North Koreans fielded more than 10 infantry divisions for the battle, most were only equivalent in strength to an infantry regiment. In contrast with the professional mechanized army that had existed at the start of the Korean War, the newly rebuilt North Korean formations were poorly trained and armed. Nevertheless, the start date of the Third Phase Campaign was set for New Year's Eve in order to take advantage of the full moon and the low alertness of the UN soldiers during the holiday.

Opening moves
On the central front, the ROK III Corps defended the 38th parallel north of Gapyeong (Kapyong) and Chuncheon. Composed of the ROK 2nd, 5th, 7th and 8th Infantry Divisions, the ROK III Corps placed the ROK 2nd Infantry Division on the corps' left flank in the hills north of Gapyeong, while the ROK 5th Infantry Division defended the corps' center at Chuncheon. The winter conditions created great difficulties for the South Korean defenders, with the heavy snow hindering construction and icy roads limiting food and ammunition resupply. North Korean guerrillas were also active in the region, and caused serious disruption in the rear of the ROK III Corps.

As part of the Chinese plan to capture Seoul, the PVA 42nd and the 66th Corps were tasked with protecting the Chinese left flank by eliminating the ROK 2nd and 5th Infantry Divisions, while cutting the road between Chuncheon and Seoul. Following instructions, the two Chinese corps struck quickly after midnight on New Year's Eve. The PVA 124th Division first penetrated the flanks of the ROK 2nd Infantry Division, then blocked the division's withdrawal route. The trapped ROK 17th and 32nd Regiments of the ROK 2nd Infantry Division were then forced to retreat in disarray. With the PVA 66th Corps pressuring the ROK 5th Infantry Division's front, the PVA 124th Division then advanced eastward in the South Korean rear and blocked the ROK 5th Infantry Division's retreat route as well. The maneuver soon left the ROK 36th Regiment of the ROK 5th Infantry Division surrounded by Chinese, and the ROK 36th Regiment had to escape by infiltrating the Chinese lines using mountain trails. By January 1, the ROK III Corps was in full retreat, while the corps' headquarters had lost contact with the 2nd and 5th Infantry Divisions. Responding to the crisis on the central front, the ROK III Corps sector's defense was handed over the US X Corps.

While the Chinese were making a concentrated attack against the South Korean front, the North Korean forces that had infiltrated the UN rear were cutting the South Korean withdrawal route. In the days before the Chinese Third Phase Campaign, the KPA II Corps established a major roadblock to the north of Hoengsong with an estimated strength of 10,000 soldiers, which blocked the retreat of the ROK III Corps. In response, the ROK II Corps and the US 2nd Infantry Division conducted a siege operation against the roadblock from both the north and the south, and the roadblock was forced open by January 2. Although the UN forces managed to eliminate a North Korean division at the roadblock, the ROK II Corps was nearly destroyed during the fighting, and it was disbanded on January 10.

The success of the initial Chinese and North Korean attacks forced the ROK I Corps to abandon its attempts to restore its original defensive position at Hyon-ri, and a large number of North Korean forces soon streamed into the gap between the US 2nd Infantry Division at Wonju and the ROK I Corps on the east coast. Ridgway interpreted the Sino-Korean attack on the central front as an attempt to surround the UN defenders at Seoul, and he immediately ordered their evacuation on January 3. On January 5, Ridgway ordered all UN forces to withdraw to the 37th parallel to set up a new defensive line, dubbed "Line D", with the UN forces on central and eastern fronts setting up defenses between Wonju and the coastal city of Jumunjin (Chumunjin). At the same time, the Chinese troops halted their offensive operations with the KPA II and V Corps relieving the PVA 42nd and 66th Corps.

Wonju falls
In the aftermath of the South Korean collapse, the KPA V Corps proceeded to launch frontal attacks against US X Corps while the KPA II Corps infiltrated the UN rear through the area to the east of Wonju. The US 2nd Infantry Division's position had now become an exposed northern salient, and its defenses were further hampered by the flat terrain surrounding Wonju. However, given the strategic importance of Wonju in controlling central Korea, Ridgway declared that the village was "only second to Seoul" in importance, and therefore must be defended at all cost. In accordance with Ridgway's instructions, Almond ordered the US 2nd Infantry Division to defend the hills north of Wonju, yet Major General Robert B. McClure of the US 2nd Infantry Division believed that the salient was untenable due to the terrain and the low morale of his division. On January 7, two infantry battalions from the KPA V Corps launched an attack against the US 2nd Infantry Division. One North Korean battalion managed to infiltrate the American positions disguised as refugees while another battalion launched a frontal assault. Yet the weak attack was soon repulsed due to the lack of coordination between the North Korean units, and about 114 infiltrators were later captured. Although the North Korean attack inflicted little damage on the Americans, the disruption caused by infiltrators in US 2nd Infantry Division's rear convinced McClure to abandon Wonju on January 7. Almond concurred with McClure's decision on the condition that the US 2nd Infantry Division would only retreat 3 mi so that Wonju could be controlled by UN artillery fire. Regardless, McClure ordered the division to retreat more than 8 mi south, putting the village out of artillery range. With Wonju under North Korean control, the Chinese declared that the Third Phase Campaign had reached a successful conclusion.

Hill 247


Hill 247 was located among the hill mass 3 mi south of Wonju, and was a critical height that commanded the streets of Wonju. With the loss of Wonju on January 7, Almond was furious at McClure for disobeying the order to hold it, and this later resulted in Major General Clark Ruffner replacing McClure on January 13. On January 8, Almond ordered the US 2nd Infantry Division to retake Wonju. Following his orders, the US 23rd Infantry Regiment, under the command of Colonel Paul L. Freeman, attacked towards Wonju on January 8. The 23rd Infantry Regiment managed to reach within 3000 yd at the south of Wonju and caught a sleeping North Korea regiment by surprise at Hill 247. About 200 North Korean soldiers were killed in the ensuing battle, however the alerted North Korean forces soon counterattacked by outflanking the 23rd Infantry Regiment to the east, and the 23rd Infantry Regiment was forced to retreat to avoid encirclement.

Encouraged by the heavy North Korean losses during the initial UN attacks, Almond again ordered the US 2nd Infantry Division to recapture Wonju on January 9. About four infantry battalions from the US 23rd and 38th Infantry Regiment supported by French and Dutch troops advanced toward Wonju on January 9, yet the attack was stalled at Hill 247 due to the cold weather and the lack of air support. As the UN forces tried to dislodge the North Koreans the next day, they were met by six defending North Korean battalions with an estimated strength of 7,000 soldiers. Under a heavy snowstorm and with no air support, the battle for Hill 247 continued for most of January 10, and the fighting around the French Battalion of the 23rd Infantry Regiment became particularly fierce. At one point, the French Battalion was forced to fend off several North Korean counterattacks with bayonet charges after running out of ammunition. The French Battalion's action at Wonju impressed Ridgway, who later encouraged all American units in Korea to utilize bayonets in battle. The North Koreans tried to encircle the attacking UN forces as the latter began to gain the upper hand, however artillery fire broke up the North Korean formations, and they had suffered an estimated 2,000 casualties in the aftermath of the battle. When air support returned on January 11, the attacking UN forces inflicted another 1,100 North Korean casualties and captured Hill 247 by January 12. Although the cold weather and the stubborn North Korean defenses prevented the UN forces from entering Wonju, the capture of Hill 247 had put all of Wonju within UN artillery range, and the village soon became a no man's land under the devastating bombardment.

Anti-guerrilla operations


Although the capture of Hill 247 had forced the KPA V Corps to abandon Wonju with heavy losses on January 17, the KPA II Corps' infiltration in the UN rear area had become so serious that it threatened to outflank the entire UN front and force a complete evacuation of Korea by mid-January. With the bulk of the US X Corps tied up to the south of Wonju while the ROK III Corps was in disarray, the front between Wonju and the east coast was undefended, and about 16,000 North Korean soldiers entered the gap while establishing guerrilla bases from Tanyang to Andong. The battles along the central front soon degenerated into irregular warfare between company-sized UN patrols and North Korean guerrilla bands. In an effort to stabilize the front, Ridgway ordered the US 2nd Infantry Division to withdraw from Wonju while pulling the central and eastern fronts back to the area between Wonju and Samch'ok, and this resulted in another 40 mi retreat. Ridgway also sent the US 187th Regimental Combat Team, the US 5th Cavalry Regiment, the US 1st Marine Division and the Greek Battalion to contain North Korean guerrillas east of Route 29 and north of Andong and Yeongdeok. About 30,000 American infantry were deployed to the central front by mid-January, and the North Korean guerrillas were blocked in a narrow salient along the hills at the east of Route 29.

To eliminate the North Korean threat in the UN rear, Almond ordered all X Corps units on Route 29 to launch aggressive patrols to destroy the North Korean supply bases and guerrilla bands. Specially trained irregular forces, such as X Corps' Special Action Group, also hunted North Korean units by operating as guerrillas themselves. The constant UN pressure slowly depleted the ammunition and the manpower of the KPA II Corps, while Major General Yu Jai Hung rallied the ROK III Corps and sealed the gap between Wonju and the east coast by January 22. On January 20, a patrol carried out by the US 9th Infantry Regiment of the US 2nd Infantry Division managed to reoccupy Wonju without much resistance. Lacking reinforcements and supplies, the KPA II Corps was scattered by the end of January, and only 8,600 soldiers from the KPA II Corps managed to survive and retreat back to North Korea. The KPA 10th Division, vanguard of the KPA II Corps, was also annihilated during the UN anti-guerrilla operations.

Aftermath
By the end of January, the KPA II Corps was decimated during its guerrilla operations, and its estimated strength was reduced from 16,000 to 8,000. The KPA V Corps' attempt to capture Wonju had also resulted in crippling casualties, and its estimated strength was reduced from 32,000 to 22,000 by the end of January. In contrast, the UN losses were relatively moderate during the same period. The defeat of the North Korean army enabled the UN forces to consolidate their positions along the Korean central and eastern front, and the retreating US Eighth Army on the Korean western front could finally return to the offensive after its rear and eastern flank were secured. As soon as the US X Corps regained full control of the central front at the end of January, Ridgway immediately ordered the US Eighth Army to launch Operation Thunderbolt against Chinese and North Korean forces on January 25, 1951.