structural:expansion, structural:scholar_edition, linguistic:voice_change, stylistic:style_transfer, linguistic:paraphrasing
Korean War

Archival material suggests that North Korea's decision to invade South Korea was Kim's initiative, not a Soviet one. Evidence suggests that Soviet intelligence, through its espionage sources in the US government and British SIS, had obtained information on the limitations of US atomic bomb stockpiles as well as defense program cuts, leading Stalin to conclude that the Truman administration would not intervene in Korea.

China acquiesced only reluctantly to the idea of Korean reunification after being told by Kim that Stalin had approved the action. The Chinese did not provide North Korea with direct military support (other than logistics channels) until United Nations troops, largely US forces, had nearly reached the Yalu River late in 1950. At the outset of the war in June and July, North Korean forces captured Seoul and occupied most of the South, save for a small section of territory in the southeast region of the South that was called the Pusan Perimeter. But in September, the North Koreans were driven back by the US-led counterattack that started with the UN landing in Incheon, followed by a combined South Korean-US-UN offensive from the Pusan Perimeter. By October, UN forces had retaken Seoul and invaded the North to reunify the country under the South. On 19 October, US and South Korean troops captured P'yŏngyang, forcing Kim and his government to flee north, first to Sinuiju and eventually into Kanggye.

On 25 October 1950, after sending various warnings of their intent to intervene if UN forces did not halt their advance, Chinese troops in the thousands crossed the Yalu River and entered the war as allies of the KPA. There were nevertheless tensions between Kim and the Chinese government. Kim had been warned of the likelihood of an amphibious landing at Incheon, which was ignored. There was also a sense that the North Koreans had paid little in war compared to the Chinese who had fought for their country for decades against foes with better technology. The UN troops were forced to withdraw and Chinese troops retook P'yŏngyang in December and Seoul in January 1951. In March, UN forces began a new offensive, retaking Seoul and advanced north once again halting at a point just north of the 38th Parallel. After a series of offensives and counter-offensives by both sides, followed by a grueling period of largely static trench warfare that lasted from the summer of 1951 to July 1953, the front was stabilized along what eventually became the permanent " Armistice Line " of 27 July 1953. Over 2.5 million people died during the Korean War.

Chinese and Russian documents from that time reveal that Kim became increasingly desperate to establish a truce, since the likelihood that further fighting would successfully unify Korea under his rule became more remote with the UN and US presence. Kim also resented the Chinese taking over the majority of the fighting in his country, with Chinese forces stationed at the center of the front line, and the Korean People's Army being mostly restricted to the coastal flanks of the front.