In August 1968, as my family took a summerlong camping trip through Europe, 500,000 troops from the Soviet Union and Eastern Bloc countries rolled into Czechoslovakia to put down what Moscow perceived as the country’s intolerable deviation from its leadership of the Warsaw Pact nations. It was tempting at the time to view this as a successful demonstration of Soviet force. After all, Moscow not only halted the rapid liberalization of Czechoslovakia—which had been driven by popular demands for