Origins of the Cold War 1945-1955

The Cold War — the decades-long ideological and geopolitical struggle between the United States and the Soviet Union — shaped the world for over forty years. CCEA Unit 2 requires you to understand how wartime allies became peacetime adversaries with such speed, and to assess which side bore greater responsibility for the tension.

The wartime alliance and its fault lines

During World War II, the USA, Britain and the Soviet Union were united by the common enemy of Nazi Germany. But beneath the surface, profound tensions existed:

• The USSR had suffered approximately 27 million deaths — a catastrophic toll that shaped Soviet determination to ensure security through buffer states in Eastern Europe.
• The USA and Britain had delayed opening a Second Front (D-Day) until June 1944 — Soviet leaders suspected this was deliberate, to let the USSR and Germany exhaust each other.
• Ideological differences were fundamental: the USA championed liberal capitalism and democracy; the USSR championed communism and one-party rule.

Yalta Conference (February 1945)

The Big Three — Roosevelt, Churchill and Stalin — met at Yalta in Crimea to plan for the post-war world:

• Germany would be divided into occupation zones (US, British, French, Soviet).
• Free elections would be held in liberated Eastern European states.
• Stalin agreed to enter the war against Japan after Germany's defeat.
• The United Nations would be established.

Key tension: The phrase "free elections" meant fundamentally different things to the Western Allies and Stalin. The West understood competitive multi-party elections; Stalin understood elections that would confirm pro-Soviet governments.

Potsdam Conference (July-August 1945)

By the time of Potsdam, the war in Europe was over. Key changes from Yalta:

• Roosevelt had died (April 1945) and was replaced by Harry Truman — a more confrontational figure.
• The atom bomb had been successfully tested (16 July 1945) — Truman hinted at this to Stalin, who already knew through Soviet spies.
• Churchill was replaced mid-conference by Clement Attlee after Labour won the UK general election.

Potsdam was marked by intense argument over reparations (how much Germany would pay) and the Eastern European states. Truman and Stalin clashed repeatedly. No lasting agreements were reached on many points.

The Iron Curtain

Between 1945 and 1948, the Soviet Union progressively installed communist-dominated governments across Eastern Europe: Poland, Czechoslovakia, Hungary, Romania, Bulgaria, East Germany, Albania. In each case, the process involved Soviet pressure, rigged elections, and the elimination of non-communist opposition.

Winston Churchill, speaking at Fulton, Missouri on 5 March 1946, declared: "From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent." The phrase became iconic — capturing the division of Europe between the Soviet sphere and the free West.

The Truman Doctrine (March 1947)

The immediate trigger was a crisis in Greece, where communist guerrillas were fighting the government, and Turkey, facing Soviet pressure on the Dardanelles strait. Britain, exhausted by WWII debt, announced it could no longer support the Greek government financially.

Truman addressed Congress on 12 March 1947, requesting $400 million in military and economic aid for Greece and Turkey. More importantly, he articulated a universal principle: "It must be the policy of the United States to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures."

This became the Truman Doctrine — the US would use economic and military aid (but not initially troops) to contain the spread of communism anywhere in the world. The policy of containment was born.

The Marshall Plan (June 1947)

Secretary of State George Marshall proposed a massive programme of US economic aid to reconstruct the war-damaged economies of Europe. The US offered $13 billion (approximately $140 billion in 2024 values) in aid across sixteen Western European countries between 1948 and 1952.

The Marshall Plan was explicitly presented as economic not ideological — open to all European states, including the USSR. Stalin refused and pressured Eastern European states to refuse as well. Stalin correctly identified that Marshall aid would bind recipients to the US economic sphere and undermine communist parties.

The Cominform response: Stalin established Cominform in 1947 to coordinate communist parties and the Soviet bloc's response to American foreign policy.

The Berlin Blockade 1948-49

Stalin's most direct response to Western policies was the Berlin Blockade (June 1948 – May 1949). Stalin cut all road and rail links to West Berlin — hoping to force the Western Allies to abandon their sectors of the city.

The Western response was the Berlin Airlift: for 11 months, US and British planes flew food and supplies into West Berlin (up to 8,000 tonnes per day). Stalin eventually lifted the blockade — a humiliation that confirmed that the West would not be bullied out of Berlin.

NATO and the arms race

In April 1949, the North Atlantic Treaty Organisation (NATO) was formed — a military alliance committing the USA to defend Western Europe. This represented a dramatic shift from pre-war US isolationism.

The Soviet Union tested its first atomic bomb in August 1949 — three years earlier than Western intelligence had predicted. The arms race was now a nuclear arms race.

Why did the Cold War start? The debate

Historians disagree about who bore primary responsibility:

• Orthodox (Western) view: Soviet expansionism in Eastern Europe and Stalin's imposition of communist satellite states caused the Cold War. Blame lies with the USSR.
• Revisionist view (William Appleman Williams et al.): American economic imperialism — the determination to keep markets open for US capitalism (Marshall Plan, Truman Doctrine) — provoked a defensive Soviet response. Blame lies with the US.
• Post-revisionist view: Both sides contributed to the Cold War through misunderstanding, mutual fear and ideological incompatibility. The war was "a tragedy of errors" not of calculated aggression.