07 The Cold War in a Divided World
Trace how the Cold War developed from postwar rivalry into a global competition, how it shaped conflicts and alliances, and how it ended with the collapse of communist rule in Eastern Europe and the dissolution of the Soviet Union.
Origins and division of Europe
The grew out of ideological differences, postwar insecurity, and competition for global influence. The United States generally promoted capitalism and electoral democracy, while the Soviet Union promoted communism under one-party rule and state ownership of major industries. Ideology was only part of the rivalry: each side also feared the other’s military power and sought security, influence, and dependable allies.
Disagreements over postwar Europe, especially the future of Germany and the political order in Eastern Europe, intensified the competition. In 1947, the United States adopted , a policy intended to prevent the spread of Soviet influence. The Truman Doctrine offered aid to countries resisting communist pressure, while the Marshall Plan funded European recovery.
The Soviet Union consolidated control across much of Eastern Europe. Its 1948–1949 blockade of West Berlin prompted a U.S.-led airlift. In 1949, the United States and its Western allies formed the North Atlantic Treaty Organization (NATO); in 1955, the Soviet Union and its allies formed the Warsaw Pact. Europe became divided into competing political and military blocs.
Nuclear rivalry and
The extended far beyond Europe. Both superpowers built large nuclear arsenals and developed alliances, intelligence networks, economic aid programs, propaganda, and military assistance. —the threat of nuclear retaliation—helped discourage direct superpower war, but also made crises dangerous. In October 1962, the deployment of Soviet nuclear missiles in Cuba brought the United States and Soviet Union close to nuclear conflict before they reached a settlement.
In , superpowers supported opposing sides in wars fought by local forces. The Korean War began in 1950 when North Korea invaded South Korea. A U.S.-led United Nations force fought on South Korea’s side, while China intervened on North Korea’s side. The 1953 armistice stopped the fighting but did not reunify Korea.
In Vietnam, U.S. intervention on behalf of South Vietnam became a major war against communist North Vietnam and its allies. The United States withdrew its forces under a 1973 peace agreement. North Vietnam took Saigon in 1975, ending the war and reunifying the country under communist rule.
Local agency and nonalignment
competition also affected newly independent countries. Superpower governments supplied aid and arms, and sometimes intervened, while local leaders pursued their own political goals and rivalries. In the Congo, independence in 1960 was followed by crisis and foreign involvement; the United States and Soviet Union competed for influence amid internal conflict.
After Soviet forces entered Afghanistan in 1979 to support the country’s government, the United States and others supported Afghan resistance fighters. The war lasted a decade and caused immense destruction. These cases show that local actors had their own agency: alignments did not make every conflict simply a contest directed by Washington or Moscow.
Many countries emerging from colonial rule sought to avoid formal alignment with either bloc. Founded in 1961, the gave states a forum to assert independence and oppose colonialism while navigating superpower pressure. Their choices shaped the , even as foreign intervention and competition sometimes aggravated local conflicts.
and the end of the
From the late 1960s into the 1970s, periods of brought reduced tension, negotiations, and arms-control agreements, although competition continued. The United States also improved relations with China, changing the diplomatic balance. Tensions rose again after the Soviet intervention in Afghanistan in 1979.
In the 1980s, Soviet leader Mikhail Gorbachev introduced reforms and reduced Moscow’s efforts to control Eastern Europe. Popular movements challenged communist governments. The Berlin Wall opened in November 1989, and communist rule collapsed across much of Eastern Europe.
The Soviet Union dissolved in December 1991, conventionally marking the end of the . The rivalry had shaped alliances, nuclear strategy, and conflicts across Europe, Asia, Africa, and Latin America. Although the United States and Soviet Union avoided direct war, their interventions and support for rival factions affected many societies; the political and human consequences endured beyond the rivalry’s end.