U.S. intelligence officials in early postwar Czechoslovakia had access to some of the Czechoslovak government's highest-ranking individuals and plenty of time to prepare for the looming confrontation with the Czechoslovak Communist Party. Yet the Communist takeover in February 1948 took them by surprise and undermined their networks. This article discusses the activities of four Czechoslovak security and intelligence agencies to demonstrate that the scale of the U.S. failure in Prague in 1945–1948 was far greater than often assumed, especially if one considers the substandard size and quality of Czechoslovakia's Communist-dominated special services after the war.

The story of the arrest and imprisonment of Vladimír Komárek sheds valuable light on relations between Czechoslovakia and the United States in the 1950s and 1960s. Komárek, who had worked as an intelligence officer against the Czechoslovak Communist regime in the 1950s, was a U.S. citizen traveling to the Soviet Union on business when he was dramatically captured by the Czechoslovak authorities. Pressure from the U.S. government and private individuals, as well as conflicts between the Czechoslovak secret service and other, more liberal, elements in the Czechoslovak government, ultimately led to Komárek's release. Czechoslovakia's eventual willingness to cooperate in the Komárek case signaled a new approach to relations with the West, an approach that would have significant consequences during the Prague Spring of 1968.