How and why did the Cold War develop, escalate and end between 1945 and 1991?
Analyse the origins, key crises, ideological conflict and eventual end of the Cold War between the United States and the Soviet Union from 1945 to 1991.
The origins, escalation, key crises and end of the Cold War between the United States and the Soviet Union, from the post-war division of Europe to the collapse of the USSR in 1991.
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What this dot point is asking
You must explain the origins of the Cold War, its key crises and the way it was conducted, and assess why it ended. Strong answers engage with the debate over who was responsible for its origins and weigh the factors behind its peaceful conclusion.
Origins and the division of Europe (1945-1949)
The wartime alliance between the USA, USSR and Britain broke down after victory over Germany in 1945. At the Yalta and Potsdam conferences (1945) the Allies disagreed over the future of Eastern Europe, especially Poland. The Soviet Union, under Joseph Stalin, installed communist governments across the territories its army occupied, while the USA, under Harry Truman, sought open markets and democracy. Winston Churchill warned in 1947 that an "iron curtain" had descended across Europe.
The USA adopted containment: the Truman Doctrine (1947) promised support to nations resisting communism, and the Marshall Plan (1947-1948) offered economic aid to rebuild Western Europe. The Soviets responded with the Berlin Blockade (1948-1949), countered by the Western airlift, after which Germany was split into West and East (1949). Military blocs formed: NATO (1949) in the West and later the Warsaw Pact (1955) in the East. In Asia, the communist victory in China (1949) and the Korean War (1950-1953) globalised the conflict.
Escalation and crises (1949-1969)
The Cold War was sustained by ideology and an arms race. Both sides built nuclear arsenals, producing the doctrine of mutually assured destruction, and competed in the space race after the Soviet launch of Sputnik (1957). Key crises brought the world close to war.
The Berlin Crisis culminated in the building of the Berlin Wall (1961), which stopped the flow of East Germans to the West and became the symbol of a divided Europe. The Cuban Missile Crisis (October 1962), triggered by Soviet missiles in Cuba, was the closest the superpowers came to nuclear war; it ended when Soviet leader Nikita Khrushchev withdrew the missiles in exchange for a US pledge not to invade Cuba and the quiet removal of US missiles from Turkey. The crisis prompted the first arms-control steps, including the 1963 Partial Test Ban Treaty.
Detente, the Second Cold War and proxy conflicts
The late 1960s and 1970s brought detente, a relaxation of tension marked by the SALT I treaty (1972) and President Nixon's visit to China (1972). Yet the conflict continued through proxy wars across the developing world, most destructively in Vietnam, where US intervention against communist forces ended in withdrawal (1973) and communist victory (1975). Detente collapsed after the Soviet invasion of Afghanistan (1979), ushering in a "Second Cold War". President Ronald Reagan increased defence spending, denounced the USSR, and announced the Strategic Defense Initiative (1983).
The end of the Cold War (1985-1991)
The Cold War ended faster than almost anyone predicted. Soviet leader Mikhail Gorbachev, taking power in 1985, faced a stagnant economy and an unaffordable arms race. His reforms, glasnost (openness) and perestroika (restructuring), and his decision not to use force to prop up Eastern European regimes, transformed the situation. Arms-control agreements such as the INF Treaty (1987) eased tension.
In 1989 communist governments fell across Eastern Europe, and the Berlin Wall was opened on 9 November 1989. Germany was reunified in 1990. Within the USSR, nationalist movements and a failed hardliner coup (August 1991) accelerated collapse, and the Soviet Union was formally dissolved in December 1991, leaving the USA the sole superpower.
Historians debate why it ended. Some credit Reagan's pressure and Western strength; others stress Gorbachev's choices, Soviet economic failure, the appeal of Western prosperity, and pressure from movements such as Solidarity in Poland. Most see a combination of long-term Soviet decline and Gorbachev's reformist decisions.
The historiography of the end of the Cold War is as contested as that of its origins. Triumphalist accounts, common in the United States, credit Reagan's military build-up and the Strategic Defense Initiative with bankrupting an over-stretched Soviet economy. Others stress that Gorbachev was not forced but chose reform and restraint, abandoning the Brezhnev Doctrine and refusing to send tanks into Eastern Europe in 1989. Economic historians emphasise structural Soviet stagnation, the burden of the Afghan war, and the failure of central planning to match Western consumer prosperity. Social historians point to the role of dissident movements, Solidarity in Poland and the churches. A strong SACE answer holds these explanations together rather than choosing one, and distinguishes long-term causes of Soviet weakness from the short-term decisions that determined the timing and peaceful nature of the collapse.
Exam-style practice questions
Practice questions written in the style of SACE Board exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
SACE 202115 marksSource A is an extract from Winston Churchill's 1946 Fulton speech warning of an iron curtain across Europe. With reference to its origin, purpose and content, analyse the usefulness of this source for a historian investigating the origins of the Cold War.Show worked answer →
A SACE Stage 2 source-analysis response wants origin, purpose and content tied to a judgement about usefulness for the stated inquiry, not a summary of the speech.
Origin and purpose. Identify Churchill as a former British Prime Minister speaking in the United States in 1946, with the purpose of alerting Western opinion to Soviet expansion and encouraging an Anglo-American alliance. This purpose makes the source persuasive and one-sided.
Usefulness. Argue it is highly useful as evidence of emerging Western perceptions and the rhetoric that hardened the divide, and as a marker of when public Cold War language began. It is less useful as a balanced account of Soviet motives, which it presents only as threat.
Make the analytical move that a persuasive source is strong evidence of attitude and intent but weak as objective fact, and cross-check against Soviet security concerns and the orthodox-revisionist debate.
Markers reward the origin-purpose-content link, a judgement relative to the question, and recognition that bias still reveals contemporary thinking.
SACE 202220 marksTo what extent was the Soviet Union responsible for the origins of the Cold War between 1945 and 1949?Show worked answer →
A 20 mark extended response needs a clear thesis weighing Soviet responsibility against other factors, sustained across structured paragraphs.
Thesis. Argue that Soviet expansion into Eastern Europe was a major cause, but that mutual fear, US economic and atomic policy and the power vacuum left by the war were also decisive.
For Soviet responsibility. Stalin's imposition of communist regimes in Poland and across the occupied territories, and the Berlin Blockade of 1948-1949, alarmed the West.
Other factors. Weigh the Truman Doctrine and Marshall Plan as provocative to Moscow, the orthodox-revisionist-postrevisionist debate, and the security concerns of a state invaded twice in thirty years.
Judgement. Conclude with a weighed verdict, for example that both superpowers contributed through misperception, but that Soviet actions in Eastern Europe were the proximate trigger.
Markers reward a weighed thesis, precise evidence and engagement with historiography in addressing "to what extent".