For the Soviet Union, the Korean War was in many ways the wrong war, as it played a crucial, yet indirect, role in it. Whatever his motivations, which centered on a realist and pragmatic appraisal of both global and regional considerations, Stalin apparently gave tacit consent to, if not outright approval for, Kim II Sung's attack on South Korea. Like China, the USSR did not want U.S. forces on its border, and sought to maintain preeminent influence in North Korea. The war had begun when the North took aggressive action semi-independently of Moscow. Another Communist state, China, then led the socialist world in it politico-military response to the Korean crisis. The Soviet Union was blamed as being both puppet master of war by the West, yet (largely unknown to the West) as insufficiently supportive by fellow Communists in China.
Campbell, Joel R.
"The Wrong War: The Soviets and the Korean War, 1945-1953,"
International Social Science Review: Vol. 88
, Article 1.
Available at: http://digitalcommons.northgeorgia.edu/issr/vol88/iss3/1