First and second battles of Wonju

The First and Second Battles of Wonju (), also known as the Wonju Campaign or the Third Phase Campaign Eastern SectorThe Western Sector is the Third Battle of Seoul. (), was a series of engagements between North Korean and Republic of Korea Army (ROKA) 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 Korean People's Army (KPA) attempted to capture Wonju in an effort to destabilize the ROKA/UN defenses along the central and the eastern fronts.

After a joint Chinese People's Volunteer Army (PVA) and KPA assault breached the ROKA/UN defenses at Chuncheon on December 31, 1950, KPA V Corps attacked US X Corps at Wonju while KPA II Corps harassed US X Corps' rear by engaging in guerrilla warfare. In response, US X Corps under the command of Major general Edward Almond managed to cripple the KPA forces at Wonju, and the UN forces later carried out a number of anti-guerrilla operations against the KPA infiltrators. In the aftermath of the battle, the KPA 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 KPA was shattered by the ROKA/UN forces following the landing at Incheon and the UN September 1950 counteroffensive, 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 and the UN offensive into North Korea prompted China to intervene in the Korean War, and Chinese forces launched their Second Phase Offensive against the ROKA/UN forces near the border during November 1950. The resulting battles in the Ch'ongch'on River valley and at Chosin Reservoir forced the ROKA/UN forces to retreat from North Korea during December 1950 to a line north of the 38th Parallel.. On the eastern front, US X Corps had evacuated North Korea by sea by December 24, 1950.. In its absence, the ROKA 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 ROKA/UN forces offered the decimated KPA a brief respite, and they rebuilt their strength at the end of 1950.

In the aftermath of the Chinese successes, Chinese Communist Party chairman Mao Zedong ordered another offensive against the ROKA/UN forces on the urging of North Korean Premier Kim Il Sung.. The offensive, dubbed the "Third Phase Campaign", was an attack 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 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..

Prelude Locations, terrain and weather The battle's main focus was around a road dubbed "Route 29", a strategically important line of communication to the ROKA/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 Taegu.. Another road, which ran from the northwest, connected Route 29 and Seoul at Wonju. Between Chuncheon and Wonju stood the town of Hoengseong, and from Wonju to Taegu 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 and snow as thick as 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 ROKA forces from Chuncheon to the east coast. Following his instructions, ROKA III Corps was placed around Chuncheon while ROKA I Corps was deployed on the east coast. Meanwhile, ROKA 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 I and III Corps. However, with the absence of US X Corps, the ROKA/UN defenses on the central and eastern fronts were stretched thin, and there were gaps between the understrength ROKA units.. Because the ROKA 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 divisions that defended Chuncheon, only one was deemed battle worthy.. Taking advantage of the situation, the KPA forces had been probing the ROKA lines since mid-December, while thousands of North Korean guerrillas harassed the ROKA/UN rear area from their mountain hideouts.. On December 27, 1950, KPA II Corps managed to move behind the UN defenses by mauling the ROKA 9th Infantry Division on I Corps' left flank at Hyon-ri. This development threatened to destabilize the entire ROKA/UN eastern front...

In order to defend against the KPA penetration, Ridgway ordered US X Corps to reinforce the ROKA defenses. However, with most of 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 at the Ch'ongch'on River. On December 28, Ridgway ordered the division to defend Wonju while placing the division under US X Corps control.. After the US 7th Infantry Division of 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 61,500 soldiers, against the ROKA/UN forces on the central front.. The KPA 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 US X Corps back in concert with the PVA attacks on Seoul, thereby isolating the ROKA forces in the Taebaek Mountains.. As part of the attacks against Seoul, the PVA 42nd and 66th Corps were deployed near Chuncheon in support of KPA V Corps during the opening phase of the battle. Meanwhile, KPA III Corps would act as reinforcements for KPA II and V Corps. However, like the ROKA they were facing, the KPA forces were also badly depleted and understrength. Although the KPA 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 KPA 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.

First Battle of Wonju Opening moves

On the central front, ROKA III Corps defended the 38th parallel north of Gapyeong (Kapyong) and Chuncheon.. Composed of the 2nd, 5th, 7th and 8th Infantry Divisions, III Corps placed the 2nd Infantry Division on the corps' left flank in the hills north of Gapyeong, while the 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 ROKA III Corps.

As part of the Chinese plan to capture Seoul, the PVA 42nd and the 66th Corps were tasked with protecting the PVA left flank by eliminating the ROKA 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 2nd Infantry Division, then blocked the division's withdrawal route.. The trapped 17th and 32nd Regiments, 2nd Infantry Division were then forced to retreat in disarray. With the PVA 66th Corps pressuring the 5th Infantry Division's front, the PVA 124th Division then advanced eastward in the rear and blocked the 5th Infantry Division's retreat route as well. The maneuver soon left the 36th Regiment, 5th Infantry Division surrounded by PVA and they had to escape by infiltrating the PVA lines using mountain trails.. By January 1, ROKA 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, ROKA III Corps sector's defense was handed over to US X Corps.

While the PVA were making a concentrated attack against the ROKA front, the KPA forces that had infiltrated the ROKA/UN rear were cutting the ROKA withdrawal route.. In the days before the Chinese Third Phase Campaign, 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 ROKA III Corps.. In response, ROKA 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 ROKA/UN forces managed to eliminate a KPA division at the roadblock, ROKA II Corps was nearly destroyed during the fighting, and it was disbanded on January 10..

The success of the initial PVA/KPA attacks forced ROKA I Corps to abandon its attempts to restore its original defensive position at Hyon-ri, and a large number of KPA soon streamed into the gap between the US 2nd Infantry Division at Wonju and ROKA I Corps on the east coast. Ridgway interpreted the 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 ROKA/UN forces to withdraw to the 37th parallel to set up a new defensive line, dubbed Line D, with the ROKA/UN forces on central and eastern fronts setting up defenses between Wonju and the coastal city of Jumunjin (Chumunjin).. At the same time, the PVA troops halted their offensive operations with KPA II and V Corps relieving the PVA 42nd and 66th Corps..

Wonju falls