How did the wartime alliance break down into a divided Europe and a global Cold War between 1945 and 1949?
the origins of the Cold War 1945 to 1949, including the wartime conferences (Yalta, Potsdam), the division of Germany and Europe, the Truman Doctrine, the Marshall Plan, the Berlin Blockade and Airlift, and the formation of NATO
A focused answer to the VCE Modern History Unit 2 dot point on the origins of the Cold War. Yalta and Potsdam, the iron curtain, Kennan's Long Telegram, the Truman Doctrine and Marshall Plan, Cominform, the Czech coup, the Berlin Blockade and Airlift, NATO, and the verdicts of John Lewis Gaddis and Melvyn Leffler.
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What this dot point is asking
VCAA expects you to explain how the wartime alliance between the US, Britain and the USSR collapsed into a structural Cold War in the four years from victory in Europe (May 1945) to the formation of NATO (April 1949). Strong responses pair the wartime conferences with the named crises (Greek civil war, Czech coup, Berlin Blockade) and cite at least one historian (Gaddis, Leffler or Westad).
The answer
The wartime alliance and Yalta
The Grand Alliance (the US, Britain and the USSR) was a marriage of convenience against Nazi Germany. It began to strain even before victory. The Tehran Conference (28 November to 1 December 1943) agreed on a second front in 1944. The Yalta Conference (4 to 11 February 1945) was attended by Roosevelt, Churchill and Stalin in the Crimea.
Yalta produced four major decisions: Germany would be occupied in four zones (US, USSR, Britain, France) and demilitarised; a Declaration on Liberated Europe promised "free elections" in liberated countries; Poland would have a reorganised provisional government and free elections "as soon as possible"; and the USSR would enter the war against Japan within three months of German defeat in exchange for territorial concessions in the Far East.
The Polish question revealed the divide. Stalin had set up the pro-Soviet Lublin Committee in July 1944. The Polish government-in-exile in London was sidelined.
Potsdam and the atomic bomb
Roosevelt died on 12 April 1945. His successor Harry Truman met Stalin and Churchill (replaced mid-conference by Clement Attlee) at Potsdam (17 July to 2 August 1945). The atmosphere had hardened. On 16 July 1945, the US successfully tested the first atomic bomb at Alamogordo, New Mexico. Truman mentioned the new weapon to Stalin on 24 July; Stalin already knew through Soviet intelligence.
Potsdam confirmed the four-zone occupation of Germany, transferred German territory east of the Oder-Neisse line to Polish administration, expelled ethnic Germans from Poland and Czechoslovakia, and set up the Council of Foreign Ministers. Reparations were to be drawn from each zone separately, foreshadowing the economic division of Germany.
The US dropped atomic bombs on Hiroshima (6 August) and Nagasaki (9 August 1945). The USSR declared war on Japan on 8 August. Japan surrendered on 15 August. The wartime alliance had achieved victory; it now had to organise the peace.
The iron curtain and the Long Telegram
Churchill, by then out of office, delivered the "Iron Curtain" speech at Fulton, Missouri on 5 March 1946: "From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent." George Kennan's "Long Telegram" from the US embassy in Moscow (22 February 1946), and his subsequent "X" article in Foreign Affairs (July 1947), argued that Soviet expansionism was structural and required "containment."
On the Soviet side, Andrei Zhdanov's "two camps" speech (September 1947) declared the world divided between the "imperialist" camp led by the US and the "democratic" camp led by the USSR.
Salami tactics in Eastern Europe
Between 1945 and 1948, communists used "salami tactics" (Matyas Rakosi's phrase) to slice opposition parties out of coalition governments. The pattern: communists took the interior ministry (controlling the police), discredited rival leaders, then engineered single-list elections.
- Poland. The provisional government included the London Poles but the secret police (UB) under Soviet supervision suppressed them. Rigged elections in January 1947 produced an 80 per cent communist bloc victory.
- Romania. A communist government was installed under King Michael's reluctant assent in March 1945; the King abdicated 30 December 1947.
- Bulgaria. A Fatherland Front government, dominated by the Bulgarian Communist Party, was confirmed in 1946.
- Hungary. The communists took the interior ministry in 1945; the prime minister Ferenc Nagy was forced out in May 1947; elections in August 1947 were fraudulent.
- Czechoslovakia. The most damaging case. Czechoslovakia had a functioning multi-party democracy under President Edvard Benes. The Communists won 38 per cent in the 1946 elections and held the interior ministry. The Prague Coup (25 February 1948) replaced the cabinet with a communist-dominated government; Foreign Minister Jan Masaryk died on 10 March 1948 in suspicious circumstances.
The Czech coup shocked the West and pushed Western European governments towards the Brussels Treaty (17 March 1948) and the negotiations that produced NATO.
The Truman Doctrine and the Greek civil war
In Greece, communist-led ELAS forces fought a civil war against the British-backed royal government (1946 to 1949). Britain told the US in February 1947 that it could no longer afford to support Greece and Turkey.
Truman addressed Congress on 12 March 1947 and announced what became the Truman Doctrine: "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." Congress voted 400 million dollars in aid to Greece and Turkey. The Greek government won the civil war by October 1949, partly after Tito's break with Stalin (June 1948) closed the Yugoslav border to ELAS.
The Marshall Plan and Cominform
The European Recovery Program ("Marshall Plan"), announced by Secretary of State George Marshall at Harvard on 5 June 1947, offered economic aid to all European states (including the USSR and Eastern Europe) in exchange for coordinated recovery plans. Stalin briefly considered participation, then forbade the Eastern bloc to join. Around 13 billion dollars was disbursed from 1948 to 1951 to 16 Western European countries.
The Soviet response was Cominform (Communist Information Bureau, September 1947), a coordinating body for European communist parties, and the Molotov Plan (1947) followed by Comecon (Council for Mutual Economic Assistance, January 1949), the Soviet bloc's economic body.
The division of Germany
The four occupation zones evolved on different tracks. The US and British zones merged into the "Bizone" on 1 January 1947 for economic administration; France joined to form the "Trizone" by April 1949.
The Western Allies introduced a new currency, the Deutschmark, in the Western zones and the Western sectors of Berlin on 20 June 1948. The Soviet response was to introduce the Ostmark and to block Western land access to Berlin.
The Berlin Blockade and Airlift (24 June 1948 to 12 May 1949)
Stalin closed all road, rail and canal access between the Western zones and West Berlin on 24 June 1948. Around 2.5 million West Berliners faced starvation. The Western Allies had three options: withdraw, force a passage, or supply by air.
Truman chose the airlift. From 26 June 1948 to 12 May 1949 (with flights continuing to 30 September 1949), the US Air Force and RAF flew around 2.3 million tons of food, coal and supplies on around 277,000 flights into Tempelhof, Gatow and Tegel airports. At peak, a plane landed every 90 seconds. American B-29 bombers, capable of carrying atomic weapons, were stationed in Britain.
Stalin lifted the blockade on 12 May 1949. The airlift was a political victory for the West and a humiliation for the USSR. Two German states followed: the Federal Republic of Germany (Basic Law, 23 May 1949; Konrad Adenauer became Chancellor on 15 September) and the German Democratic Republic (7 October 1949).
The North Atlantic Treaty Organization (4 April 1949)
The Brussels Treaty (17 March 1948), signed by Britain, France, Belgium, the Netherlands and Luxembourg, was a five-power defence pact. Negotiations to expand it into a transatlantic alliance produced the North Atlantic Treaty, signed in Washington on 4 April 1949 by 12 states (the Brussels Five plus the US, Canada, Italy, Portugal, Denmark, Norway and Iceland).
Article 5 committed each member to treat an armed attack on any one as an attack on all. NATO was the first peacetime military alliance the US had ever entered. The Soviet response (the Warsaw Pact) came only in 1955 after West Germany joined NATO.
Historiography
John Lewis Gaddis (We Now Know, 1997; The Cold War, 2005) is the leading post-revisionist. With access to Soviet archives, he emphasises Stalin's ideological hostility and personality as primary causes.
Melvyn Leffler (A Preponderance of Power, 1992) stresses American national-security planning. American policymakers sought a global system of friendly states and a favourable balance of power; that vision clashed with Soviet aims.
Odd Arne Westad (The Global Cold War, 2005) reframes the Cold War as a global ideological contest in which the Third World was not peripheral but central from the start.
William Appleman Williams (The Tragedy of American Diplomacy, 1959) was the foundational revisionist, arguing American "Open Door" capitalism drove the conflict.
Examples in context
Example 1. Salami tactics and the Prague Coup (1948) as a worked illustration of how the bloc was built. Read the pattern, communists taking the interior ministry and police, then engineering single-list elections, as a case study in the dot point's "division of Europe" theme. Czechoslovakia is the sharpest example: a functioning democracy under Benes where the Communists held 38 per cent and the interior ministry until the Prague Coup (25 February 1948) and the suspicious death of Jan Masaryk. The shock pushed the West toward the Brussels Treaty and NATO, showing cause (Soviet bloc-building) and consequence (Western alliance).
Example 2. The Berlin Blockade and Airlift (1948-1949) as a study in crisis management without war. Read the airlift, around 2.3 million tons on around 277,000 flights with a landing every 90 seconds at peak, as a worked illustration of the first direct superpower confrontation. Stalin lifted the blockade without gaining his aim, and two German states followed. Reframed as an example, it shows the dot point's point that the Cold War was fought through pressure and prestige rather than open combat.
Try this
Q1. "The United States was more responsible than the USSR for the origins of the Cold War." To what extent do you agree? [10 marks]
- Cue. Thesis: responsibility shared, but Stalin's bloc-building was the immediate trigger. Evidence US: the Truman Doctrine, Marshall Plan and the Deutschmark; evidence Soviet: salami tactics and the Czech coup; cite Gaddis (post-revisionist) and Leffler.
Q2. Explain the significance of the Marshall Plan (1947). [4 marks]
- Cue. Around 13 billion dollars offered to all Europe but refused for the Eastern bloc by Stalin; it rebuilt Western markets, hardened the divide, and prompted the Soviet Cominform and Comecon responses.
Q3. Analyse how 1949 institutionalised the division of Europe. [6 marks]
- Cue. The Berlin Blockade ended in May; two German states formed (FRG May, GDR October); NATO signed (4 April 1949) with Article 5; the first peacetime US alliance, with the Warsaw Pact response coming only in 1955.
Exam-style practice questions
Practice questions written in the style of VCAA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Practice VCAA10 marksEvaluate the extent to which the United States was responsible for the origins of the Cold War between 1945 and 1949.Show worked answer →
A 10-mark "evaluate" needs a thesis, multiple causes, and a named historian.
- Thesis
- Both superpowers contributed. American economic and atomic dominance reshaped Europe, but Soviet security demands in Eastern Europe and ideological hostility on both sides made conflict structural rather than accidental.
- Conferences
- Yalta (February 1945) accepted Soviet influence in Eastern Europe in exchange for a paper promise of "free elections." Potsdam (17 July to 2 August 1945) revealed the cracks: Truman replaced Roosevelt, the US tested the atomic bomb on 16 July.
- American actions
- Kennan's Long Telegram (22 February 1946) urged "containment." The Truman Doctrine (12 March 1947) committed the US to "support free peoples." The Marshall Plan (5 June 1947) offered 13 billion dollars; Stalin forbade bloc participation. The Bizone and the Deutschmark (20 June 1948) consolidated a Western Germany.
- Soviet actions
- Salami tactics installed communist regimes across Eastern Europe, climaxing with the Czech coup (25 February 1948). Cominform (September 1947) coordinated bloc parties. The Berlin Blockade (24 June 1948 to 12 May 1949) tested Western will.
- Western response
- The Berlin Airlift flew 2.3 million tons of supplies. NATO was signed on 4 April 1949. Two German states followed in 1949.
- Historiography
- Post-revisionists (John Lewis Gaddis, We Now Know, 1997) emphasise Stalin's ideology after the opening of Soviet archives. Melvyn Leffler (A Preponderance of Power, 1992) stresses American security policy.
- Conclusion
- By 1949 Europe was divided, Germany split, NATO existed; responsibility was shared, but Stalin's bloc-building was the immediate trigger.
Practice VCAA4 marksExplain the significance of the Berlin Blockade and Airlift (1948 to 1949).Show worked answer →
A 4-mark "explain the significance" needs the event and two consequences.
The event. On 24 June 1948, Stalin closed all road, rail and canal access to West Berlin in response to the introduction of the Deutschmark in the Western zones (20 June 1948). The US and Britain ran the Berlin Airlift from 26 June 1948 to 12 May 1949, flying 2.3 million tons of food, coal and supplies on around 277,000 flights. Stalin lifted the blockade on 12 May 1949.
Significance. (1) The first direct superpower confrontation of the Cold War without shots being fired; it set a pattern of crisis management. (2) It produced two German states: the Federal Republic of Germany (23 May 1949) and the German Democratic Republic (7 October 1949). NATO was signed on 4 April 1949, partly in response.
