| This thesis explains why the USSR, PRC, and DPRK refrained from war in Korea in summer 1949 but formed an offensive war coalition and launched a coordinated attack against the ROK in summer 1950. Dramatic shifts in structural properties of the international system in late 1949-early 1950, i.e., its bipolarization, rigidification of Cold War alliances, and intensifying security dilemma faced by the communist camp, created an increasingly threatening and war-prone international environment fraught with strategic uncertainties and war traps. This new situation aggravated Soviet and Chinese insecurities in Northeast Asia and strengthened the ability of the DPRK leaders to manipulate their patrons' perceptions of threats and opportunities in Korea for their own benefit.Pyongyang persuaded its Great Power allies to commit themselves to armed unification of Korea by changing their perceived payoff structure from the Korean war, by lengthening the perceived shadow of their future in Korea through offering them a bigger stake in the form of alliance treaties with a unified Korea, by playing off against each other their competing traditional interests in the peninsula, by highlighting the reputational cost that they would have to pay if they did not vigorously support the cause of communist-led Korean unification, and, finally, by persuading them that offense had gained a strategic advantage over defense, in contrast to the situation in 1949.Besides North Korean manipulations, in the final analysis, it was Stalin's and Mao Zedong's own insecurity that made them acquiesce to Kim Il Sung's plans. They perceived that the window of opportunity for the spread of communist revolution, opened in Korea in the wake of WWII, was rapidly closing. Consequently, they decided to align themselves tightly with the DPRK and initiate hostilities in Korea in summer 1950 because of a fear that their strategic offensive advantage might not last and, should they wait longer, their own client, North Korea, could become an object of attack from the South backed by its American ally, both intent on rolling back communist gains in East Asia. |
