Although the Cold War (1946–1991) divided the world into rival blocs, some nations preferred nonalignment. They avoided affiliation with either the United States and its First World allies or the Soviet Union and its Second World partners. Some of these nonaligned nations were traditional neutrals, such as Switzerland or Sweden, that stayed out of war. By the mid-1950s, however, many of the nonaligned were newly independent countries of Asia or Africa, numerous enough that they became known as the Third World.

Nonalignment sometimes made U.S. officials uneasy. During the 1950s Secretary of State John Foster Dulles criticized nonaligned nations for making a "shortsighted" or even "immoral" choice by not taking sides in what Dulles believed was a global contest between godless Communism and the "free world." He also disliked nonaligned leaders, such as Egypt's Gamel Abdel Nasser, who tried to exploit superpower rivalry by accepting aid from...