The Cold War from the Soviet Union's view (25 January 1951)
Historical Map of Russia & the former Soviet Union
At the end of World War II, Korea had been divided into a communist North and a pro-Western South. In June 1950, North Korea invaded the South, sparking the first major war of the Cold War. The U.S. and its allies came to South Korea's aid, but their counter-invasion of the North was turned back by a massive intervention by China. By mid-1951, the line between the Koreas was roughly back to where it had been at the start and an armistice was signed in 1953.
End of East Turkestan Republic
On 24 August 1949, the five leaders of the East Turkestan Republic (ETR) boarded a plane for Moscow to negotiate the position of the republic in the new People's Republic of China (PRC). On 3 September, the Soviet Union informed the Chinese government that the plane had crashed, killing all on board. Saifuddin Azizi, the new leader of the ETR but also a member of the Chinese Communist Party, kept the tragedy secret until December, by which time the People's Liberation Army had arrived in the region. On 18 December, the PRC dissolved the ETR, although the Soviet Union retained concessions in East Turkestan until 1954.
Outbreak of Korean War
At dawn on Sunday, 25 June 1950, the armed forces of the People's Democratic Republic of Korea (North Korea) crossed the 38th parallel into the Republic of Korea (South Korea), under the pretense that the South Koreans had attacked them. Heavily outnumbered and weak in modern weaponry, the South Korean forces were quickly overrun, abandoning Seoul on 28 June.
UN Offensive in Korea
On 15 September 1950, United Nations forces landed at Inchon, South Korea, completely outflanking the bulk of the North Korean troops, who were fighting 240 km to the southeast at the Pusan Perimeter. With the North Koreans in full retreat, the UN retook Seoul by 25 September, crossed the 38th parallel on 9 October, and captured the North Korean capital of Pyongyang on 19 October. On 26 October, South Korean forces reached Chosan on the Yalu River, the border with China.
Chinese intervention in Korea
On 25 October 1950, the Chinese People's Volunteer Army (PVA) launched the First Phase Campaign, attacking United Nations forces in North Korea before withdrawing. This was followed by the Second Phase Campaign on 25 November, in which the PVA drove the UN from much of North Korea, retaking Pyongyang in early December. The Third Phase Campaign began in late December, with the PVA crossing the 38th Parallel and recapturing Seoul on 4 January 1951.