To many Americans, the cold war is ancient history. Yet only a few decades ago the planet was dangerously divided between West and East, and the antagonism between the U.S. and the Soviet Union defined global politics. Flare-ups such as the Korean “police action,” which killed millions of people in the early 1950s, and the Cuban missile crisis, 10 years later, drew the American and Soviet governments and their proxies to the threshold of nuclear war.