The Third Battle of Seoul was a battle of the Korean War, which took place from December 31, 1950, to January 7, 1951, around the South Korean capital of Seoul. It is also known as the Chinese New Year's Offensive, the January–Fourth Retreat () or the Third Phase Campaign Western SectorThe Eastern Sector is the First and Second Battles of Wonju. ().
In the aftermath of the major Chinese People's Volunteer Army (PVA) victory at the Battle of the Ch'ongch'on River, the United Nations Command (UN) started to contemplate the possibility of evacuation from the Korean Peninsula. Chinese Communist Party chairman Mao Zedong ordered the Chinese People's Volunteer Army to cross the 38th Parallel in an effort to pressure the UN forces to withdraw from South Korea.
On December 31, 1950, the Chinese 13th Army attacked the Republic of Korea Army (ROKA)'s 1st, 2nd, 5th and 6th Infantry Divisions along the 38th Parallel, breaching ROKA/UN defenses at the Imjin River, Hantan River, Gapyeong and Chuncheon in the process. To prevent the PVA forces from overwhelming the defenders, the US Eighth Army now under the command of Lieutenant general Matthew B. Ridgway evacuated Seoul on January 3, 1951.
Although PVA forces captured Seoul by the end of the battle, the Chinese invasion of South Korea galvanized the UN support for South Korea, while the idea of evacuation was soon abandoned by the UN Command. At the same time, the PVA were exhausted after months of nonstop fighting since the start of the Chinese intervention, thereby allowing the UN forces to regain the initiative in Korea. The city would change hands one more time in Operation Ripper.
Background
With China entering the Korean War in late 1950, the conflict had entered a new phase. To prevent North Korea from falling under UN control after the UN offensive into North Korea, the PVA entered North Korea and launched their Second Phase Offensive against the ROKA/UN forces near the Sino-Korean border on 25 November. The resulting battles at the Ch'ongch'on River Valley and the Chosin Reservoir forced the ROKA/UN forces to retreat from North Korea during December 1950, with PVA and North Korean Korean People's Army (KPA) forces recapturing much of North Korea. On the Korean western front, after the US Eighth Army's defeat at the Ch'ongch'on River, it retreated back to the Imjin River while setting up defensive positions around the South Korean capital of Seoul. Although the Eighth Army was ordered to hold Seoul for as long as possible, UN commander General Douglas MacArthur planned a series of withdrawals to the Pusan Perimeter if UN forces were about to be overwhelmed. General Walton Walker, commander of the Eighth Army, was killed in a traffic accident on December 23, and Lieutenant general Matthew B. Ridgway assumed command of the Eighth Army on December 26, 1950. At the UN, a ceasefire along the 38th Parallel was proposed to China on December 11, 1950, in order to avoid any further escalation of hostility between the US and China.
Although the PVA had been weakened from their earlier battles, with nearly 40 percent of its forces rendered combat ineffective, its unexpected victories over the UN forces had convinced the Chinese leadership of the invincibility of the PVA. Immediately after the PVA 13th Army's victory over the Eighth Army at the Ch'ongch'on River, Chinese Communist Party chairman Mao Zedong started to contemplate another offensive against the ROKA/UN forces on the urging of North Korean Premier Kim Il Sung. After learning of MacArthur's plans and the UN ceasefire proposal Mao believed that the UN evacuation of the Korean Peninsula was imminent. Although the over-stretched Chinese logistics prevented the PVA from launching a full-scale invasion against South Korea, Mao still ordered the PVA 13th Army to launch an attack, dubbed the "Third Phase Campaign", to hasten the UN withdrawal and to demonstrate China's desire for a total victory in Korea. On December 23, 1950, China's Foreign Minister Zhou Enlai formally rejected the UN ceasefire while demanding all UN forces to be withdrawn from the Korean Peninsula.
Prelude Locations, terrain, and weather Korea as a whole is roughly bisected into northern and southern halves by the Han River. Seoul is located south of the 38th Parallel. The battle was fought over the ROKA/UN defenses at the 38th Parallel, which stretches horizontally from the Imjin River mouth on the Korean west coast to the town of Chuncheon in central Korea. Route 33 runs south across the 38th Parallel at the Hantan River, passes through Uijeongbu and eventually arrives at Seoul, and it is an ancient invasion route towards Seoul. Another road ran across the Imjin River, and it connects Seoul and Kaesong through the towns of Munsan and Koyang. Finally, a road runs through Chuncheon and it connects to Seoul from the northeast. The harsh Korean winter, with temperatures as low as , had frozen the Imjin and the Hantan River over most of the river crossings, eliminating a major obstacle for the attacking Chinese forces.
Forces and strategies
By December 22, 1950, the US Eighth Army's front had stabilized along the 38th Parallel. Just days before his death, Walker placed US I Corps, US IX Corps, and ROKA III Corps of the Eighth Army along the 38th Parallel to defend Seoul. US I and IX Corps were to defend the Imjin and Hantan River respectively, while ROKA III Corps were to guard the areas around Chuncheon. The boundary between US I and IX Corps was marked by Route 33, and was defended by the ROKA 1st Infantry Division on the west side and the ROKA 6th Infantry Division on the east side.
Because the ROKA forces had suffered nearly 45,000 casualties at the end of 1950, most of their units were composed of raw recruits with little combat training. After inspecting the front just days before the battle, General J. Lawton Collins, the US Army Chief of Staff, concluded that most of the ROKA formations were only fit for outpost duties. At the same time, the Eighth Army was also suffering from low morale due to its earlier defeats, and most of its soldiers were anticipating an evacuation from Korea. The Eighth Army's lack of will to fight and to maintain contact with Chinese forces resulted in a lack of information on PVA troop movements and intentions. After inspecting the front on December 27, Ridgway ordered US I and IX Corps to organize a new defensive line around Koyang to Uijeongbu, called the Bridgehead Line, to cover the Han River crossings in case the UN forces were forced to evacuate Seoul.
The PVA, however, were also suffering from logistics problems and exhaustion after their earlier victories. Arguing against the Third Phase Campaign on December 7, PVA Commander Peng Dehuai telegraphed to Mao that the PVA would need at least three months to replace its casualties, while most of its troops were in critical need of resupply, rest and reorganization. The Chinese logistics system, which was based on the concept of People's War with the native population supplying the army, also ran into difficulties due to the indifferent and sometimes hostile, Korean population near the 38th Parallel. The PVA were now suffering from hunger and the lack of winter clothing.
Responding to Peng's concern over the troops' conditions, Mao limited the scope of the Third Phase Campaign to pin down the ROKA forces along the 38th Parallel while inflicting as much damage as possible. Upon noticing that the US units were not interspersed between the ROKA formations, therefore unable to support them, Mao ordered the PVA 13th Army to destroy the ROKA 1st Infantry Division, the ROKA 6th Infantry Division and ROKA III Corps. Following Mao's instruction, Peng placed the PVA 38th, 39th, 40th and 50th Corps of the 13th Army in front of the 1st and 6th Infantry Divisions, while the 42nd and the 66th Corps of the 13th Army were moved into III Corps' sector. The start date of the offensive was set to 31 December in order to take advantage of the night assault under a full moon and the anticipated low alertness of the ROKA/UN soldiers during the holiday. For the same reasons Ridgway had predicted that 31 December would be the likely time for the new Chinese offensive. Believing that the destruction of the ROKA forces at the 38th Parallel would render the UN forces incapable of counterattacks in the future, Mao promised to pull all Chinese troops off the front line for rest and refit by the end of the campaign.
Battle On the evening of December 31, 1950, the PVA 13th Army launched a massive attack against the ROKA forces along the 38th Parallel. Along the Imjin River and the Hantan River, the PVA 38th, 39th, 40th and 50th Corps decimated the ROKA 1st Division while routing the ROKA 6th Division. At the Chuncheon sector, the PVA 42nd and the 66th Corps forced ROKA III Corps into full retreat. With the defenses at the 38th Parallel completely collapsed by January 1, 1951, Ridgway ordered the evacuation of Seoul on January 3.
Actions at the Imjin River and the Hantan River
By December 15, 1950, the ROKA 1st Infantry Division had retreated back to the town of Choksong on the southern bank of the Imjin River, its original defensive position at the start of the Korean War. On the right flank of the division, the ROKA 6th Infantry Division was located at the north of Dongducheon along the southern bank of the Hantan River. The 1st Infantry Division planned to defend the Imjin River by placing its 11th and 12th Regiments at the west and the east side of Choksong respectively, while the 6th Infantry Division defended the Route 33 at the Hantan River by placing its 7th and 19th Regiments on each side of the road. Both the 15th Regiment, 1st Infantry Division and the 2nd Regiment, 6th Infantry Division were placed in the rear as reserves. The South Koreans had also constructed numerous bunkers, barbed wire obstacles and minefields on both banks of the river in order to strengthen defenses and to maintain troop morale.
Faced with the South Korean defense, the Chinese had prepared for well over a month for the offensive. In the weeks before the operational orders for the Third Phase Campaign were issued by PVA High Command, the advance elements of the PVA 39th Corps had been conducting detailed reconnaissance on the ROKA defenses. The ROKA positions were then thoroughly analyzed by PVA commanders, engineers and artillery officers. PVA "thrust" companies, which were composed of specially trained assault and engineer teams, were also organized to lead the attack across the Imjin and Hantan River. During the preparation, the PVA artillery units had suffered heavy losses under UN air attacks, but PVA Deputy Commander Han Xianchu still managed to bring up 100 artillery pieces against the ROKA fortifications. On December 22, the PVA High Command issued the operational orders that signaled the start of the Third Phase Campaign. The PVA 39th and 50th Corps were tasked with the destruction of the 1st Infantry Division, while the 38th and the 40th Corps were tasked with the destruction of the 6th Infantry Division.