World War II and the cold war provided the context for the emergence of the United States as a global superpower, playing a role that has often been compared to that of Great Britain in the nineteenth century. Much of that effort was driven by the perceived demands of the cold war, during which the United States spearheaded the Western effort to contain a worldwide communist movement that seemed to be advancing. By 1970, one writer observed, “the United States had more than 1,000,000 soldiers in 30 countries, was a member of four regional defense alliances and an active participant in a fifth, had mutual defense treaties with 42 nations, was a member of 53 international organizations, and was furnishing military or economic aid to nearly 100 nations across the face of the globe.”12

The need for quick and often secret decision making gave rise in the United States to a strong or “imperial” presidency and a “national security state,” in which defense and intelligence agencies acquired great power within the government and were often unaccountable to Congress. This served to strengthen the influence of what U.S. president Dwight Eisenhower (1953–1961) called the “military-industrial complex,” a coalition of the armed services, military research laboratories, and private defense industries that both stimulated and benefited from increased military spending and cold war tensions.

Sustaining this immense military effort was a flourishing U.S. economy and an increasingly middle-class society. The United States was the only major industrial country to escape the physical devastation of war on its own soil. As World War II ended with Europe, the Soviet Union, and Japan in ruins, the United States was clearly the world’s most productive economy. “The whole world is hungry for American goods,” wrote one American economist in 1945.13 Beyond their goods, Americans sent their capital abroad in growing amounts—from $19 billion in 1950 to $81 billion in 1965. Huge American firms such as General Motors, Ford, Mobil, Sears, General Electric, and Westinghouse established factories, offices, and subsidiaries in many countries and sold their goods locally. The U.S. dollar replaced the British pound as the most trusted international currency.

Accompanying the United States’ political and economic penetration of the world was its popular culture. In musical terms, first jazz, then rock-and-roll, and most recently rap have found receptive audiences abroad, particularly among the young. By the 1990s, American movies took about 70 percent of the market in Europe, and in 2012 some 33,000 McDonald’s restaurants in 119 countries served 68 million customers every day. Various American brand names—Kleenex, Coca-Cola, Jeep, Spam, Nike, Kodak—became common points of reference around the world. English became a global language, while American slang terms—“groovy,” “crazy,” “cool”—were integrated into many of the world’s languages.

On the communist side, the cold war was accompanied by considerable turmoil both within and among the various communist states. Joseph Stalin, Soviet dictator and acknowledged leader of the communist world in general, died in 1953 as that global conflict was mounting. His successor, Nikita Khrushchev, stunned his country and communists everywhere with a lengthy speech delivered to a party congress in 1956 in which he presented a devastating account of Stalin’s crimes, particularly those against party members. These revelations shocked many of the party faithful, for Stalin had been viewed as the “genius of all time.” Now he was presented as a criminal.

In the Soviet Union, the superpower of the communist world, the cold war justified a continuing emphasis on military and defense industries after World War II and gave rise to a Soviet version of the military-industrial complex. Soviet citizens, even more than Americans, were subject to incessant government propaganda that glorified their system and vilified that of their American opponents.

As the communist world expanded, so too did divisions and conflicts among its various countries. Many in the West had initially viewed world communism as a monolithic force whose disciplined members meekly followed Soviet dictates in cold war solidarity against the West. And Marxists everywhere contended that revolutionary socialism would erode national loyalties as the “workers of the world” united in common opposition to global capitalism. Nonetheless, the communist world experienced far more bitter and divisive conflict than did the Western alliance, which was composed of supposedly warlike, greedy, and highly competitive nations.

In Eastern Europe, Yugoslav leaders early on had rejected Soviet domination of their internal affairs and charted their own independent road to socialism. Fearing that reform might lead to contagious defections from the communist bloc, Soviet forces actually invaded their supposed allies in Hungary (1956–1957) and Czechoslovakia (1968) to crush such movements. In the early 1980s, Poland was seriously threatened with a similar action. The brutal suppression of these reform movements gave credibility to Western perceptions of the cold war as a struggle between tyranny and freedom and badly tarnished the image of Soviet communism as a reasonable alternative to capitalism.

Even more startling, the two communist giants, the Soviet Union and China, found themselves sharply opposed, owing to territorial disputes, ideological differences, and rivalry for communist leadership. The Chinese bitterly criticized Khrushchev for backing down in the Cuban missile crisis, while to the Soviet leadership, Mao was insanely indifferent to the possible consequences of a nuclear war. In 1960, the Soviet Union backed away from an earlier promise to provide China with the prototype of an atomic bomb and abruptly withdrew all Soviet advisers and technicians, who had been assisting Chinese development. By the late 1960s, China on its own had developed a modest nuclear capability, and the two countries were at the brink of war, with the Soviet Union hinting at a possible nuclear strike on Chinese military targets. Their enmity certainly benefited the United States, which in the 1970s was able to pursue a “triangular diplomacy,” easing tensions and simultaneously signing arms control agreements with the USSR and opening a formal relationship with China. Beyond this central conflict, a communist China in fact went to war against a communist Vietnam in 1979, while Vietnam invaded a communist Cambodia in the late 1970s. Nationalism, in short, proved more powerful than communist solidarity, even in the face of cold war hostilities with the West.

Despite its many internal conflicts, world communism remained a powerful global presence during the 1970s, achieving its greatest territorial reach. China was emerging from the chaos of the Cultural Revolution. The Soviet Union had matched U.S. military might; in response, the Americans launched a major buildup of their own military forces in the early 1980s. Despite American hostility, Cuba remained a communist outpost in the Western Hemisphere, with impressive achievements in education and health care for its people. Communism triumphed in Vietnam, dealing a major setback to the United States. A number of African countries affirmed their commitment to Marxism. Few people anywhere expected that within two decades most of the twentieth century’s experiment with communism would be gone.