"The Cold War’s first hot war began on June 25, 1950. Following almost two years of armed skirmishes between North and South Korea, that day ninety thousand North Korean troops crossed the thirty-eighth parallel. They easily captured Seoul two days later and threatened to overrun the southern part of the peninsula. During the two preceding months, the North Korean communist leader Kim Il Sung had obtained Stalin’s assent and the Kremlin’s promises of military support for theinvasion as well as an endorsement from Mao. But the timing was the North Korean’s alone, and the invasion created a cascade of surprises for all the major parties."