As late as early 1948, the Truman administration had no intention of creating an “entangling” peacetime alliance. NATO was a European idea pressed upon U.S. officials. It was also a frantic response to fast-breaking crises—namely the Czech coup in February 1948 and the Berlin blockade in June—that terrified the Europeans and convinced the Truman administration that nothing short of a formal defense treaty could buck them up against Soviet pressure.

