The Cold War: origins and development 1941-1956

These revision notes cover how the Cold War began and developed between 1941 and 1956. They cover the wartime Grand Alliance and its strains, the three wartime conferences, Soviet control of Eastern Europe, the hardening of attitudes in 1946-47, the division of Germany and Europe, the spread of the conflict to Asia through the Korean War, and the Warsaw Pact and Hungarian Rising of 1956. They are written for two parts of Cambridge International AS & A Level History (9489). The first is Paper 3 (Interpretations), in the topic on the origins and development of the Cold War, 1941-1950. The second is the Cold War material in the Paper 4 international history depth study (1945-1991). Sections 10 and 11 (1950-1956) are relevant to Paper 4 only. The notes also suit other A Level courses that cover the same period. They include a dated timeline, the main historical interpretations with named historians, guidance on reading a Paper 3 extract, essay plans for three typical "to what extent / how far" questions, a glossary and a quick check with answers.

1. How to use these notes

Examiners on this period reward three skills: accurate, precise knowledge (dates, names, what was actually agreed), analysis (why something happened and how much it mattered) and judgement (a supported answer to "how far"). The historiography section has two jobs. In Paper 4 essays it helps you explain why historians disagree. In Paper 3 it helps you recognise and explain a historian's interpretation in an extract. Do not just list historians. Use their arguments to test your own judgement.

Key idea: what "Cold War" means

The Cold War was a long period of hostility, from about 1945 to 1991, between the USA and its allies on one side and the USSR and its allies on the other. The two superpowers never fought each other directly in a full-scale war. Instead they competed through alliances, propaganda, economic aid, an arms race, espionage and proxy wars. At its root was a clash between two systems: liberal-democratic capitalism and one-party communism with a state-run economy.

2. The wartime alliance and its tensions, 1941-1945

How the Grand Alliance formed

• 22 June 1941: Germany invaded the USSR (Operation Barbarossa). Churchill offered Britain's support at once, even though he had been strongly anti-communist all his life.
• August 1941: Roosevelt and Churchill issued the Atlantic Charter. It promised self-determination and no territorial gains after the war. Later, the Western powers used these principles to judge Soviet behaviour in Eastern Europe.
• Late 1941: the USA extended Lend-Lease aid to the USSR.
• December 1941: Japan attacked Pearl Harbor (7 December), and Germany declared war on the USA (11 December). The "Big Three" (the USA, Britain and the USSR) were now allies.

The alliance held together because the three powers shared one enemy. It was not based on shared values, and the tensions grew as victory came closer.

Sources of tension inside the alliance

Issue	Soviet view	Western view
The "second front"	Stalin demanded an Anglo-American invasion of France from 1942 to take pressure off the Red Army. He suspected the West was delaying on purpose so that the USSR would be bled dry.	Britain and the USA argued that they were not ready. They chose North Africa (1942) and Italy (1943) first. D-Day did not come until 6 June 1944.
Poland	The USSR wanted to keep the eastern Polish lands it had taken in 1939 and wanted a "friendly" government in Warsaw. In 1944 it backed the communist-dominated Lublin Committee.	Britain had gone to war over Poland and recognised the Polish government-in-exile in London.
Katyn (1943)	When the London Poles asked for an investigation into the mass graves of Polish officers found at Katyn, Moscow broke off relations with them (April 1943). The USSR blamed Germany.	Western leaders privately suspected Soviet guilt but kept quiet to protect the alliance. The USSR admitted responsibility only in 1990.
Warsaw Uprising (August-October 1944)	The Red Army stayed on the eastern side of the Vistula. Stalin called the rising a reckless adventure.	Many in the West believed Stalin had let the Germans destroy the non-communist Polish resistance.
Deep-rooted mistrust	Soviet leaders remembered Western intervention in the Russian Civil War (1918-20), appeasement and the Munich Agreement (1938).	Western leaders remembered the Nazi-Soviet Pact (1939) and Comintern activity aimed at spreading revolution.

The Percentages Agreement, October 1944

At a meeting in Moscow, Churchill and Stalin informally agreed on "percentages" of influence in the Balkans. Examples included 90% Soviet influence in Romania, 90% British influence in Greece and a 50-50 split in Yugoslavia. Roosevelt was not a party to it. Stalin largely kept to it over Greece: he did not openly back the Greek communists when British troops intervened in December 1944. Historians use the agreement in two ways. Some argue that Stalin thought in traditional spheres-of-influence terms rather than in terms of world revolution. Others argue that the Western powers themselves accepted a divided Europe.

3. The wartime conferences: Tehran, Yalta and Potsdam

Tehran (28 November - 1 December 1943)

• This was the first meeting of Roosevelt, Churchill and Stalin together.
• The Western Allies agreed to invade France (Operation Overlord) in May 1944, so Stalin finally got a date for the second front.
• Stalin agreed to join the war against Japan once Germany was defeated.
• They agreed in principle to move Poland's borders westward: the USSR would keep eastern Poland roughly up to the Curzon Line, and Poland would gain German land in the west.
• There was early discussion of a post-war international organisation (the future United Nations).

Significance: this was the high point of co-operation. Roosevelt often sided with Stalin rather than Churchill, but the Polish question was left vague.

Yalta (4-11 February 1945)

• Germany: to be divided into occupation zones, with France now given a zone carved out of the British and US zones. Berlin, which lay inside the Soviet zone, would be under joint Allied occupation. (Sectors in Berlin had been agreed in 1944, and a French sector was added in mid-1945.) Germany would be demilitarised and denazified.
• Reparations: agreed in principle. A figure of $20 billion, half of it to the USSR, was accepted only as a basis for discussion.
• Poland: the eastern border would roughly follow the Curzon Line. The Soviet-backed provisional government would be reorganised "on a broader democratic basis", and "free and unfettered elections" would be held.
• Declaration on Liberated Europe: liberated peoples would choose their own governments through free elections.
• Japan: the USSR would enter the war against Japan within about three months of Germany's defeat. In return it would get southern Sakhalin, the Kurile Islands and rights in Manchuria.
• United Nations: agreement on the Security Council veto for the great powers and on a founding conference (San Francisco, April 1945).

Significance: Yalta looked like a success at the time. However, the key phrases ("democratic", "free elections") meant different things to each side. For Stalin, a "democratic" Poland meant one that was friendly to the USSR. For the West, it meant multi-party elections. Later American critics claimed that Roosevelt had "given away" Eastern Europe. Defenders of Roosevelt point out that the Red Army already occupied Poland and much of south-eastern Europe.

Changes between Yalta and Potsdam

• 12 April 1945: Roosevelt died. His successor, Harry Truman, had little experience of foreign affairs and was more openly suspicious of the USSR. On 23 April he spoke bluntly to Soviet Foreign Minister Molotov about Poland.
• 8 May 1945: Germany surrendered. The shared enemy that had held the alliance together was gone.
• May 1945: Lend-Lease shipments to the USSR were abruptly cut back, which angered Moscow.
• 16 July 1945: the USA successfully tested an atomic bomb in New Mexico.

Potsdam (17 July - 2 August 1945)

• The participants were Truman, Stalin and Churchill. Churchill was replaced part-way through by Clement Attlee after Labour won the British general election.
• The zones of Germany and the sectors of Berlin were confirmed. The Allied Control Council would govern Germany as a whole. Policy would follow the "Ds": denazification, demilitarisation, democratisation and decentralisation (including breaking up large industrial combines).
• Reparations: each power would take reparations mainly from its own zone. The USSR would also receive a share of industrial equipment from the western zones, partly in exchange for food and raw materials from the east.
• Poland's western border: Poland would administer German land up to the Oder-Neisse line until a final peace settlement. Germans were to be moved out of Poland, Czechoslovakia and Hungary "in an orderly and humane manner".
• On 24 July Truman told Stalin, in vague terms, about a powerful new weapon. Stalin already knew about it through Soviet espionage.

Significance: Potsdam was far less friendly than Yalta. The reparations compromise meant that in practice Germany began to be run as separate zones. The atomic bombings of Hiroshima (6 August) and Nagasaki (9 August), and the Soviet declaration of war on Japan (8 August), followed soon after. Revisionist historians argue that the USA used the bomb partly to impress the USSR ("atomic diplomacy").

Conference	Leaders	Main agreements	Main disagreements	Mood
Tehran 1943	Roosevelt, Churchill, Stalin	Second front in 1944; USSR to fight Japan; Poland's borders to move west	Detail on Poland left unclear	Co-operative
Yalta 1945	Roosevelt, Churchill, Stalin	Occupation zones, including one for France; Declaration on Liberated Europe; UN; USSR to fight Japan	Make-up of Poland's government; size of reparations	Outwardly co-operative, with vague wording
Potsdam 1945	Truman, Stalin, Churchill then Attlee	Four Ds; Oder-Neisse line (provisional); reparations mainly from own zone	Poland; Eastern European governments; reparations; the atomic bomb	Suspicious and tense

4. Soviet expansion into Eastern Europe, 1944-1949

By 1945 the Red Army occupied most of Eastern and Central Europe. Over the next four years pro-Soviet communist governments were set up across the region. The usual method was gradual. First came a broad "coalition" or "national front" government. Communists took key ministries, especially the interior ministry, which controlled the police. Then rival parties were split, discredited or banned, and elections were rigged. The Hungarian communist leader Mátyás Rákosi later called this "salami tactics", slicing away the opposition one piece at a time.

Country	Key developments
Poland	Soviet-backed provisional government from 1945 with a few London Poles added. The opposition, led by Mikołajczyk's Peasant Party, was harassed, and the elections of January 1947 were rigged. Mikołajczyk fled later that year.
Romania	Soviet pressure forced the king to appoint a pro-communist government under Petru Groza (March 1945). The king abdicated in December 1947.
Bulgaria	The Communist-led Fatherland Front dominated. The monarchy was abolished in 1946, and the opposition leader Nikola Petkov was executed in 1947.
Hungary	The Smallholders' Party won the free election of November 1945 with a clear majority. The communists, backed by Soviet forces, then broke up their rivals step by step. By 1949 Hungary was a one-party state under Rákosi.
Czechoslovakia	The communists were the largest party in the fairly free 1946 election. In February 1948 they took full power in a coup. Foreign Minister Jan Masaryk was found dead in March 1948. This shocked Western opinion and helped the Marshall Plan pass through Congress.
East Germany (Soviet zone)	The Communists and Social Democrats were merged into the SED in 1946 under communist control. The zone became the German Democratic Republic in 1949.
Yugoslavia	Tito's partisans liberated the country largely by themselves. Tito's independence led to his expulsion from Cominform in June 1948, which shows the limits of Soviet control.

Key idea: interpreting Soviet motives

Security explanation: the USSR had lost perhaps 25-27 million people in the war and had been invaded through Poland twice in 30 years. A "buffer zone" of friendly states was a defensive necessity.

Ideological or expansionist explanation: communist rule was imposed by force, against the wishes of most people, and in breach of the Yalta promise of free elections. This suggests a drive to spread communism.

Many post-Cold War historians, for example Zubok and Pleshakov, combine the two. In their view Stalin wanted security, but his idea of "security" required communist-controlled regimes.

5. The hardening of attitudes, 1946

Stalin's election speech (9 February 1946)

Stalin argued that capitalism made future wars inevitable and called for rapid rebuilding of heavy industry. Some in Washington read it as a declaration of ideological hostility.

Kennan's Long Telegram (22 February 1946)

• George Kennan was a senior diplomat at the US embassy in Moscow. He sent a very long cable to the State Department analysing Soviet behaviour.
• He argued that Soviet hostility came from a traditional Russian sense of insecurity, and that Marxist-Leninist ideology justified this hostility. Soviet leaders needed an outside enemy to justify their dictatorship at home.
• The USSR would therefore push outwards wherever it could, but it was cautious and would retreat when it met strong resistance.
• Kennan developed the idea publicly in the "X Article", "The Sources of Soviet Conduct" (Foreign Affairs, July 1947), which made "containment" the basis of US policy.

Churchill's "Iron Curtain" speech (5 March 1946)

• Churchill was no longer Prime Minister. He gave the speech at Westminster College, Fulton, Missouri, and Truman was on the platform.
• He said that "from Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the Continent". The states behind it were under growing control from Moscow.
• He called for a "fraternal association" of the English-speaking peoples to stand firm, and he argued that the Soviets respected strength.
• Stalin responded in Pravda by comparing Churchill to Hitler and calling the speech a call to war.

Other 1946 flashpoints

• Iran: Soviet troops stayed in northern Iran after the agreed withdrawal date. After strong US and UN pressure they left in spring 1946. This seemed to confirm Kennan's view that firmness worked.
• Turkey: in 1946 the USSR pressed for joint control of the Turkish Straits. The USA responded by sending naval forces to the eastern Mediterranean.
• Novikov Telegram (September 1946): the Soviet ambassador in Washington reported that the USA was seeking world domination. It was a mirror image of Kennan's analysis.
• Germany: in May 1946 the US military governor stopped reparations deliveries from the US zone to the USSR. In September the US Secretary of State, Byrnes, signalled in a speech at Stuttgart that the USA would stay in Europe and rebuild Germany's economy.

6. The Truman Doctrine and the Marshall Plan, 1947

The Truman Doctrine (12 March 1947)

• Background: in February 1947 Britain told the USA that it could no longer afford to support the Greek government in its civil war against communist guerrillas, or to support Turkey.
• Truman asked Congress for $400 million in aid for Greece and Turkey.
• He described the world as divided between two ways of life and declared that it must be US policy "to support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures".
• Significance: it was an open-ended commitment to containment worldwide. It ended any return to isolationism and presented the conflict in ideological terms. Ironically, Stalin gave the Greek communists little direct help, and much of their support came from Tito's Yugoslavia.

The Marshall Plan (European Recovery Program)

• Secretary of State George Marshall announced it in a speech at Harvard University on 5 June 1947.
• Europe was in economic crisis after the very harsh winter of 1946-47. There was hunger and a shortage of dollars, and communist parties were strong in France and Italy.
• Aid was offered to all of Europe, including the USSR. However, it required shared planning, open economic information and co-operation among the recipient states.
• At the Paris talks in July 1947 Molotov walked out, and Soviet pressure made Poland and Czechoslovakia withdraw their interest.
• Sixteen Western European states took part in the planning. The Organisation for European Economic Co-operation (OEEC), set up in April 1948, also included the western zones of Germany. About $13 billion was given between 1948 and 1952.
• Truman described the Truman Doctrine and the Marshall Plan as "two halves of the same walnut": one military and political, the other economic.

Key idea: "dollar imperialism"

The Soviet leadership called the Marshall Plan "dollar imperialism". In their view it was a way of making Europe economically dependent on the USA, opening markets for American goods and pulling Eastern Europe out of the Soviet sphere. Revisionist historians stress the same economic motives. Orthodox historians see it as generous and as a response to real need and to the communist threat.

7. The Soviet response: Cominform and Comecon

Organisation	Founded	Purpose	Significance
Cominform (Communist Information Bureau)	September 1947 (founding meeting in Poland)	To co-ordinate nine leading communist parties (those of the USSR, Poland, Czechoslovakia, Hungary, Romania, Bulgaria, Yugoslavia, France and Italy) under Moscow's direction	Andrei Zhdanov's "two camps" speech presented the world as split into an imperialist camp led by the USA and an anti-imperialist camp led by the USSR. Cominform was used to expel Tito in 1948 and was dissolved in 1956.
Comecon (Council for Mutual Economic Assistance)	January 1949	The Soviet economic answer to the Marshall Plan, linking the economies of the Soviet bloc	It gave far less aid than the Marshall Plan. In practice it tied Eastern European trade to the USSR. Together with the earlier "Molotov Plan" trade deals, it split Europe economically.

8. Germany divided: the Berlin Blockade and Airlift, 1948-1949

Background

• The four-power Control Council could not agree on how to run Germany. The USSR wanted reparations and a weak Germany. The Western powers increasingly wanted German economic recovery to help Europe recover.
• January 1947: the British and US zones merged economically to form Bizonia. The French zone joined in 1948-49 (Trizonia).
• Early 1948: at the London conference the Western powers moved towards creating a West German state.
• June 1948: a new currency, the Deutschmark, was introduced in the western zones (announced 18 June, in use from 20 June) and then in West Berlin.

The Blockade

• From 24 June 1948 the USSR cut all road, rail and canal links between the western zones and West Berlin. It also cut the electricity supply from the east.
• Stalin's likely aims: to force the Western powers to drop plans for a West German state, or to leave Berlin altogether.
• The Western response: Truman rejected both withdrawal and sending an armed convoy through, which risked war. Instead the USA and Britain supplied West Berlin by air. At its peak, aircraft landed every few minutes. In total around 2.3 million tons of supplies were flown in on more than 270,000 flights. US B-29 bombers were also sent to Britain as a signal of resolve.
• The blockade was lifted on 12 May 1949.

Consequences

• It was a propaganda defeat for the USSR and a triumph for the West, especially the USA.
• It sped up the creation of NATO and of the two German states, which was the opposite of what Stalin wanted.
• It set a pattern of crisis management. Both sides avoided direct fighting even at moments of high tension.

9. NATO, two German states and the Soviet bomb, 1949

NATO (North Atlantic Treaty Organization), 4 April 1949

• Its forerunner was the Brussels Treaty of March 1948, signed by Britain, France, Belgium, the Netherlands and Luxembourg.
• Twelve founding members: the USA, Canada, Britain, France, Belgium, the Netherlands, Luxembourg, Norway, Denmark, Iceland, Italy and Portugal.
• Article 5: an armed attack on one member would be treated as an attack on all. This is an example of collective defence.
• Significance: this was the USA's first peacetime military alliance outside the Americas, and its first alliance with European states since the French alliance of 1778. (The 1947 Rio Pact had already linked the USA to Latin American states.) NATO committed the USA to the defence of Western Europe and broke with the tradition of avoiding "entangling alliances".

The two German states

Federal Republic of Germany (West Germany)	German Democratic Republic (East Germany)
Created	May 1949 (Basic Law, 23 May); first government September 1949	7 October 1949
Leader	Chancellor Konrad Adenauer (Christian Democrat)	Walter Ulbricht (deputy premier; SED General Secretary from 1950) was the dominant figure. Wilhelm Pieck was President and Otto Grotewohl Prime Minister.
System	Multi-party parliamentary democracy with a market economy	One-party communist state with a planned economy
Alliance	Joined NATO in May 1955	Founding member of the Warsaw Pact in 1955

The Soviet atomic bomb (29 August 1949)

• The USSR tested its first atomic bomb years earlier than most American officials had expected, helped in part by information from spies.
• The US nuclear monopoly was over, and an arms race began. Truman approved work on the hydrogen bomb in January 1950. The USA tested one in November 1952, and the USSR tested its own thermonuclear device in August 1953.
• Together with the communist victory in China (People's Republic proclaimed 1 October 1949), the Soviet bomb created a sense of crisis in Washington. This produced NSC-68 (April 1950), a policy paper calling for a massive increase in US military spending.

10. The Korean War: the Cold War spreads to Asia, 1950-1953

Sections 10 and 11 go beyond 1950. For Cambridge 9489 they are relevant to the Paper 4 depth study, not to the Paper 3 Interpretations topic.

Background

• Korea, ruled by Japan from 1910, was divided at the 38th parallel in 1945. Soviet forces occupied the north and US forces the south.
• In 1948 two states were created: the Republic of Korea in the south under Syngman Rhee, and the Democratic People's Republic of Korea in the north under Kim Il Sung. Both claimed the whole peninsula.
• In January 1950 Secretary of State Dean Acheson described a US "defensive perimeter" in the Pacific that did not include Korea.
• Evidence from Soviet archives shows that Stalin approved Kim's plan to invade in spring 1950, provided Mao agreed to support it.

Main stages

1. 25 June 1950: North Korea invaded the South and captured Seoul.
2. The UN Security Council condemned the invasion and called on members to help South Korea. The USSR could not veto this because it was boycotting the Council over the UN's refusal to give China's seat to the People's Republic. A UN force led by the USA, under General MacArthur, was sent.
3. UN forces were pushed back to a small area around Pusan in the south-east.
4. 15 September 1950: MacArthur's landing at Inchon cut North Korean supply lines. UN forces crossed the 38th parallel and advanced towards the Yalu River on the Chinese border. The aim had changed from containment to "rollback".
5. October-November 1950: Chinese "People's Volunteers" entered the war in large numbers. Their offensives from late November drove UN forces back south of the 38th parallel by December 1950, and Seoul fell again in January 1951.
6. April 1951: Truman dismissed MacArthur for publicly calling for an expanded war against China. The front stabilised near the 38th parallel, and truce talks began in July 1951.
7. 27 July 1953: an armistice was signed at Panmunjom, after Stalin's death in March 1953 and Eisenhower's election. The border ended up close to where it had started. No peace treaty was ever signed.

Why the Korean War mattered to the Cold War

• It turned containment into a global and military policy. NSC-68 was put into effect, and US defence spending rose from about $13 billion a year (1950) to about $50 billion (1953), roughly a fourfold increase.
• It led to the rearmament of West Germany being discussed seriously, and NATO gained a unified military command.
• It brought hostility between the USA and the People's Republic of China, which lasted until the 1970s. The USA committed itself to protecting Taiwan.
• It was the first "limited war" of the nuclear age. Both sides kept the fighting within Korea.
• It strengthened McCarthyism and anti-communist feeling inside the USA.

11. After Stalin: the Warsaw Pact and the Hungarian Rising, 1953-1956

A "thaw"?

• 5 March 1953: Stalin died, and a collective leadership followed. Nikita Khrushchev gradually emerged as the leading figure.
• June 1953: a workers' uprising in East Germany was crushed by Soviet tanks.
• Signs of easing tension included the Korean armistice (1953) and the Austrian State Treaty (May 1955), under which all four occupying powers withdrew in return for Austrian neutrality. Another was the Geneva Summit (July 1955), the first meeting of Soviet and Western heads of government since Potsdam.
• Khrushchev spoke of "peaceful coexistence" with the West.

The Warsaw Pact (14 May 1955)

• It was formed days after West Germany joined NATO (May 1955).
• Members: the USSR, Poland, East Germany, Czechoslovakia, Hungary, Romania, Bulgaria and Albania.
• It was a military alliance under a unified command led by the USSR. It gave a legal basis for keeping Soviet troops in Eastern Europe.
• With it, the division of Europe into two armed blocs was complete.

De-Stalinisation

At the 20th Party Congress (February 1956), Khrushchev's public main report accepted that there could be "different roads to socialism". He had already conceded this idea to Tito in the Belgrade Declaration of 1955. Then, in his closed "Secret Speech" on 25 February, he denounced Stalin's personality cult and crimes. Eastern Europeans took these signals as a sign that change was possible. In Poland, riots at Poznań (June 1956) were followed in October by the return of the reform-minded Władysław Gomułka. Soviet troops moved towards Warsaw and Khrushchev flew there on 19 October, but in the end he accepted Gomułka because Poland stayed communist and in the Warsaw Pact.

The Hungarian Rising (October-November 1956)

1. Background: Rákosi's harsh Stalinist rule had caused hardship. He was removed in July 1956, but his replacement, Ernő Gerő, was also a hardliner.
2. 23 October 1956: student demonstrations in Budapest in support of Poland turned into a national uprising. Stalin's statue was pulled down.
3. 24 October: Imre Nagy, a reform communist, became Prime Minister. On the same day, at Gerő's request, Soviet troops already stationed in Hungary entered Budapest, but they met fierce resistance and failed to crush the rising. After a ceasefire they withdrew from the capital at the end of October.
4. Nagy went further than Gomułka. He brought non-communists into government, promised free elections and, on 1 November, announced that Hungary would leave the Warsaw Pact and become neutral.
5. 4 November 1956: Soviet forces invaded in large numbers and crushed the rising. János Kádár was installed as leader. Thousands of Hungarians were killed, and around 200,000 fled abroad. Nagy was later tried in secret and executed (1958).
6. Western response: Radio Free Europe and US talk of "liberation" had encouraged Hungarians, but the West gave no military help. The West was also divided by the Suez Crisis, which was happening at the same time, and the USA was unwilling to risk war in a Soviet sphere.

Key idea: the lesson of 1956

Hungary showed that the USSR would permit limited reform (as in Poland) but not departure from the Warsaw Pact or the end of one-party communist rule. It also showed that, despite its rhetoric, the USA in practice accepted the Soviet sphere in Eastern Europe. Many historians conclude that containment, not rollback, was real US policy.

12. Timeline, 1941-1956

Date	Event
22 June 1941	Germany invades USSR (Operation Barbarossa)
August 1941	Atlantic Charter (Roosevelt and Churchill)
7-11 December 1941	Pearl Harbor; USA enters the war; Germany declares war on USA
April 1943	USSR breaks relations with London Poles over Katyn
28 Nov - 1 Dec 1943	Tehran Conference
6 June 1944	D-Day: second front opened in France
August - October 1944	Warsaw Uprising
October 1944	Churchill-Stalin Percentages Agreement
4-11 February 1945	Yalta Conference
12 April 1945	Death of Roosevelt; Truman becomes President
8 May 1945	Germany surrenders (VE Day)
16 July 1945	First US atomic test
17 July - 2 August 1945	Potsdam Conference
6 and 9 August 1945	Atomic bombs on Hiroshima and Nagasaki; USSR declares war on Japan (8 August)
9 February 1946	Stalin's election speech
22 February 1946	Kennan's Long Telegram
5 March 1946	Churchill's Iron Curtain speech, Fulton
January 1947	Bizonia created; rigged Polish elections
12 March 1947	Truman Doctrine
5 June 1947	Marshall Plan announced
July 1947	Kennan's "X Article"; Molotov leaves Paris talks
September 1947	Cominform founded
February 1948	Communist coup in Czechoslovakia
March 1948	Brussels Treaty
April 1948	OEEC set up
June 1948	Deutschmark introduced; Tito expelled from Cominform; Berlin Blockade begins (24 June)
January 1949	Comecon founded
4 April 1949	NATO founded
12 May 1949	Berlin Blockade lifted
May 1949	Federal Republic of Germany founded
29 August 1949	First Soviet atomic test
1 October 1949	People's Republic of China proclaimed
7 October 1949	German Democratic Republic founded
April 1950	NSC-68
25 June 1950	North Korea invades South Korea
15 September 1950	Inchon landing
October 1950 - January 1951	Chinese intervention in Korea; UN forces pushed back south of the 38th parallel; Seoul lost again
April 1951	MacArthur dismissed
5 March 1953	Death of Stalin
June 1953	East German uprising crushed
27 July 1953	Korean armistice, Panmunjom
May 1955	West Germany joins NATO; Warsaw Pact (14 May); Austrian State Treaty
June 1955	Belgrade Declaration: Khrushchev reconciles with Tito
July 1955	Geneva Summit
February 1956	20th Party Congress: "different roads to socialism" (public report); Khrushchev's Secret Speech (25 February)
June - October 1956	Poznań riots; Gomułka returns to power in Poland
23-24 October 1956	Hungarian Rising begins; Nagy becomes Prime Minister; first Soviet intervention in Budapest
Late October 1956	Ceasefire; Soviet troops withdraw from Budapest
1 November 1956	Nagy announces Hungary will leave the Warsaw Pact
4 November 1956	Full Soviet invasion of Hungary; Kádár installed

13. Interpretations: who was responsible for the Cold War?

School	Main argument	Historians often associated with it	Context of the writing
Orthodox (traditional)	The USSR was mainly to blame. Stalin's expansionism and communist ideology threatened the West, and US policy was a necessary, defensive reaction.	Herbert Feis; Thomas A. Bailey; Arthur Schlesinger Jr (his 1967 article "Origins of the Cold War" defended the orthodox view against the revisionists)	Late 1940s-1960s, at the height of the Cold War. Historians often worked closely with the US government's own view.
Revisionist	The USA bore much of the responsibility. It sought open markets and economic dominance ("Open Door"), used the atomic bomb to pressure the USSR, and misread Soviet security needs as aggression.	William Appleman Williams (The Tragedy of American Diplomacy, 1959); Gar Alperovitz (Atomic Diplomacy, 1965); Gabriel Kolko; Walter LaFeber	Late 1950s-1970s. Its roots lay in New Left criticism of US capitalism and foreign policy (Williams, 1959). The Vietnam War then made many more historians critical of US foreign policy.
Post-revisionist	Both sides share responsibility. Mutual misunderstanding, clashing security needs and the power vacuum left in 1945 made conflict very likely. Neither side fully understood the other's fears.	John Lewis Gaddis (The United States and the Origins of the Cold War, 1941-1947, 1972); Melvyn Leffler, who stresses US ideas of "national security"	1970s-1980s. The period of détente, when more US documents became available.
Post-Cold War research (sometimes called "new orthodoxy" or post-post-revisionism)	Soviet archives opened after 1991. Some historians returned to stressing Stalin's personal role and ideology. Others described a Soviet mix of security concerns and revolutionary ambitions.	Gaddis (We Now Know, 1997); Vladislav Zubok and Constantine Pleshakov ("revolutionary-imperial paradigm")	1990s onwards. New evidence, for example on Stalin's approval of the Korean invasion.

Labels are simplifications. Individual historians' views developed over time. Gaddis in particular moved from a post-revisionist position in 1972 towards greater emphasis on Stalin in 1997. Kennan, whose analysis shaped containment, later criticised its militarisation. In an essay, credit the argument to the historian or school, and explain the evidence behind it.

Using these interpretations in Paper 3

Paper 3 (Interpretations) is not an essay on the events. You are given one extract from a historian and asked to identify and explain that historian's interpretation and approach. The question is worth [40].

1. Explain the interpretation, not the topic. The most common mistake is to write a narrative of events. Every paragraph should say what the historian argues and show how the extract reveals it. Use your own knowledge to explain the extract's references, not to replace them.
2. Look for clues to the school.
   • Where is the blame placed? Mainly on Stalin (orthodox), mainly on the USA (revisionist), or on both (post-revisionist)?
   • What drives events? Ideology and expansion (orthodox), economic interests such as open markets and the "Open Door" (revisionist), or security fears and misperception (post-revisionist)?
   • How is the other side presented? Revisionists present Soviet actions as defensive. Orthodox writers present US actions as a reaction.
   • What evidence is used? References to Soviet archives, or to Stalin's personal role and beliefs, suggest post-1991 work.
3. Read the whole extract. Find the overall argument first, then the supporting points. Watch for qualifications ("however", "although"), which often show a post-revisionist balance.

Worked example: reading a short extract

Invented extract: "Washington's leaders did not need to invent a Soviet menace, but they found it useful. A Europe closed to American goods was the nightmare that haunted them after 1945. Aid to Europe was generous in form, yet it was offered on terms that Moscow could only refuse. The division that followed was therefore not forced on the United States; it was the price Washington was willing to pay for an open, capitalist Western Europe."

Model explanation (4 sentences): The historian argues that the USA carries the main responsibility for the division of Europe, which is a revisionist interpretation. The stress on the fear of "a Europe closed to American goods" shows an economic approach close to Williams's "Open Door" argument. The claim that Marshall Aid was offered "on terms that Moscow could only refuse" suggests the rejection was designed into the plan, so Soviet behaviour is presented as a reaction rather than as aggression. The phrase "did not need to invent a Soviet menace" accepts some real Soviet threat, but the historian still judges that the US chose division for its own interests.

Worked example: using historiography in a paragraph

Question focus: Was the Marshall Plan an act of generosity or of American self-interest?

Step 1: make a clear point. "The Marshall Plan can be seen as serving US economic interests as much as European recovery."

Step 2: support it with precise evidence. "About $13 billion was given in 1948-52. Much of it was spent on American goods, and the terms required recipients to share economic information and co-operate in planning. Stalin saw this as incompatible with Soviet control."

Step 3: link it to an interpretation. "This supports the revisionist argument, associated with William Appleman Williams, that US policy aimed at an 'Open Door' for American trade."

Step 4: test the interpretation. "However, aid was offered to the USSR and Eastern Europe as well. The winter of 1946-47 had caused real hardship, and there was a genuine fear that communist parties in France and Italy would win power legally. The orthodox view, that the plan was a defensive response to economic collapse and communist opportunity, therefore also has strong support."

Step 5: reach a mini-judgement. "The plan is best seen as enlightened self-interest. A prosperous, capitalist Western Europe was in America's economic and security interests at the same time, which fits the post-revisionist emphasis on security."

14. Essay planning

In the Cambridge 9489 Paper 4 depth study, each essay is worth [30]. For "to what extent" and "how far" questions, examiners reward a balanced argument that reaches a supported judgement. Your judgement must answer the exact question asked, including its dates and its key term. A reliable structure:

1. Introduction: define the key terms, set out the factors and state your line of argument (your overall judgement).
2. Paragraphs on the stated factor: the case for, with precise evidence.
3. Paragraphs on other factors: the case against, or alternative explanations.
4. End each paragraph with a mini-judgement about how important that factor was.
5. Conclusion: weigh the factors against each other. Do not just summarise. Explain why one mattered most.

Essay plan 1: "To what extent was Stalin responsible for the outbreak of the Cold War by 1949?"

Line of argument (one possible answer): Stalin bears the largest single share of responsibility because of the way he imposed communist rule in Eastern Europe, but US policy from 1947 turned mutual suspicion into a formal division.

Case for Stalin's responsibility

• Broke the Yalta promise of free elections: Poland 1947, salami tactics in Hungary, the Czech coup of 1948.
• Pressure on Iran and Turkey in 1946.
• Rejected the Marshall Plan and forced satellite states to do the same; set up Cominform and Comecon.
• Berlin Blockade 1948-49: an aggressive attempt to force the West out.
• Historians: the orthodox school; Gaddis (1997) after the Soviet archives opened.

Case against / other factors

• Soviet security needs: enormous war losses, invasion through Poland, the Percentages Agreement accepted by Churchill.
• US actions: the abrupt cut in Lend-Lease, "atomic diplomacy", ending reparations from the US zone (1946), Bizonia, the Deutschmark.
• Ideological framing by the West: the Iron Curtain speech; the Truman Doctrine's "two ways of life".
• Historians: revisionists (Williams, Alperovitz); post-revisionists stress mutual misperception (for example, the Long Telegram and the Novikov Telegram as mirror images).

Possible judgement: Stalin's methods in Eastern Europe were the main cause of Western alarm. However, the Cold War became an open, formal division because of how the two sides reacted to each other in 1947-49. Responsibility was shared but unequal.

Essay plan 2: "How far was the division of Germany the main reason for the hardening of the Cold War between 1945 and 1949?"

Line of argument: Germany was the central issue because both sides saw its future as decisive for the balance of power in Europe. However, the German question was part of a wider breakdown over Eastern Europe and economic recovery.

Case for Germany as main reason

• Disputes over reparations from Yalta to Potsdam; the Control Council breaking down.
• Byrnes's Stuttgart speech (1946); Bizonia (1947); the London conference and the Deutschmark (1948).
• The Berlin Blockade: the first direct superpower confrontation, which led to NATO.
• Two separate German states created in 1949, which fixed the division of Europe.

Other factors

• Eastern Europe: Poland, Czechoslovakia, the Iron Curtain.
• Ideology and perceptions: the Long Telegram, Zhdanov's "two camps".
• The Truman Doctrine and Marshall Plan as a turning point in 1947.
• The atomic bomb: the US monopoly until August 1949.

Possible judgement: the Marshall Plan in 1947 was arguably the turning point that made division certain. Germany was where that division was most dangerous and most visible. The two factors are closely linked, because the plan required a recovering western Germany.

Essay plan 3: "To what extent did Soviet policy towards Eastern Europe change between 1953 and 1956?"

Line of argument: the style of Soviet policy changed after Stalin's death, but its basic aim of keeping communist regimes loyal to Moscow did not.

Evidence of change

• The "New Course" after 1953 and collective leadership; Khrushchev's peaceful coexistence.
• Austrian State Treaty and Soviet withdrawal (1955); reconciliation with Tito in the Belgrade Declaration (1955).
• 20th Party Congress (February 1956): "different roads to socialism" in the public report, and the Secret Speech; Cominform dissolved (April 1956).
• Gomułka accepted in Poland in October 1956, after Soviet threats of force were dropped.

Evidence of continuity

• East German uprising crushed (June 1953).
• Warsaw Pact (1955) made Soviet military control formal.
• Hungary: Soviet troops intervened in Budapest on 24 October 1956. After Nagy's announcement that Hungary would leave the Warsaw Pact, the full invasion of 4 November installed a new loyal leader, Kádár.

Possible judgement: change was real in tone and tactics, and there was more room for national variation. But Hungary showed the limits. Membership of the Warsaw Pact and one-party rule could not be questioned, so the change was limited.

Key terms

Term	Definition
Grand Alliance	The wartime alliance of the USA, Britain and the USSR against Nazi Germany, 1941-45.
Second front	An Anglo-American invasion of western Europe, which Stalin demanded to relieve pressure on the Red Army. It came on D-Day, June 1944.
Sphere of influence	An area in which one great power has dominant political, economic or military influence over other states.
Buffer zone	A group of friendly states between a power and its potential enemies, intended to protect it from invasion.
Salami tactics	The step-by-step removal of non-communist rivals in Eastern Europe until the communists held full power.
Iron Curtain	Churchill's phrase (1946) for the dividing line between Soviet-controlled Eastern Europe and the West.
Containment	US policy, based on Kennan's analysis, of preventing any further spread of Soviet or communist influence.
Truman Doctrine	Truman's 1947 pledge to support free peoples resisting subjugation by armed minorities or outside pressure.
Marshall Plan (European Recovery Program)	US economic aid to rebuild European economies, 1948-52.
Dollar imperialism	The Soviet term for the use of US economic aid to gain political control over other states.
Cominform	The Communist Information Bureau (1947-56), which co-ordinated nine leading European communist parties under Moscow's direction.
Comecon	The Council for Mutual Economic Assistance (1949), linking the economies of the Soviet bloc.
Bizonia	The economic merger of the British and American zones of Germany in January 1947.
Airlift	The supply of West Berlin by air during the Soviet blockade, June 1948 - May 1949 (continued for some months afterwards).
Collective security	A system in which all member states agree to act together against any state that commits aggression, including one of their own members, as in the League of Nations and the UN Charter.
Collective defence	An alliance whose members agree to defend each other against attack from outside, as in NATO's Article 5.
NSC-68	A 1950 US National Security Council paper calling for a large military build-up to contain communism globally.
Limited war	A war fought with restricted aims and area, deliberately stopping short of total or nuclear war, as in Korea.
Rollback / liberation	The idea of pushing communism back from territory it already controlled, rather than just containing it.
Peaceful coexistence	Khrushchev's policy that communist and capitalist states could compete without war.
De-Stalinisation	The criticism of Stalin and the partial reversal of his methods after the 20th Party Congress and Khrushchev's Secret Speech of 1956.
Orthodox / revisionist / post-revisionist	The three main schools of interpretation of the origins of the Cold War. They mainly blame, respectively, the USSR, the USA, or both sides together.

Quick check

The marks below show only how much depth each answer needs. They do not follow the Cambridge 9489 mark scheme. In the real papers, AS essays are marked out of 10 ("explain why") and 20 ("to what extent / how far"), the Paper 3 extract question out of 40, and Paper 4 essays out of 30. Answers 10-12 are outline answers, not full essays.

1. State the date of the German invasion of the USSR, which began the Grand Alliance. [1]
2. Identify two decisions about Germany made at the Yalta Conference. [2]
3. Name the diplomat who wrote the Long Telegram, and state the policy his ideas led to. [2]
4. Describe what Churchill claimed in his Fulton speech of March 1946. [3]
5. Explain why the Soviet Union rejected Marshall Aid. [4]
6. Explain why the Western powers chose an airlift, rather than an armed convoy, to respond to the Berlin Blockade. [4]
7. Explain why the Soviet Union was unable to veto UN action in Korea in June 1950. [3]
8. Compare the reactions of the Soviet leadership to events in Poland and Hungary in October-November 1956. [5]
9. Explain why relations between the wartime allies became worse between the Yalta and Potsdam conferences. [6]
10. Assess the importance of 1949 as a turning point in the development of the Cold War. [8]
11. Explain how the revisionist interpretation of the Cold War's origins differs from the orthodox interpretation, and why it emerged when it did. [8]
12. "The Korean War turned the Cold War into a global conflict." To what extent do you agree? Outline your argument and judgement. [10]

1. 22 June 1941 (Operation Barbarossa).

2. Any two of: Germany to be divided into occupation zones, with a zone for France; joint Allied occupation of Berlin; Germany to be demilitarised and denazified; reparations agreed in principle, with $20 billion as a basis for discussion and half to the USSR.

3. George Kennan, at the US embassy in Moscow (February 1946). His ideas led to containment.

4. He claimed that an "iron curtain" had come down across Europe "from Stettin in the Baltic to Trieste in the Adriatic". The states east of it were increasingly controlled by Moscow. The Soviets respected strength, so Britain and the USA should work closely together to stand firm against them.

5. The aid required recipients to share economic information and co-operate in joint planning. Stalin saw this as a way for the USA to gain influence over the Soviet and Eastern European economies, and so over their politics ("dollar imperialism"). Accepting it would have weakened Soviet control of the buffer zone. It was also linked to the rebuilding of western Germany, which the USSR feared. Molotov walked out of the Paris talks in July 1947, and Poland and Czechoslovakia were pressured to withdraw.

6. An armed convoy along the land routes risked a direct military clash with Soviet forces and possibly a new war. An airlift used the air corridors agreed earlier, so the Soviets could stop it only by shooting down aircraft, which would put the blame for escalation on them. It kept West Berlin supplied, showed Western determination and won a propaganda victory without firing a shot.

7. The USSR was boycotting the Security Council in protest at the UN's refusal to give China's seat to the new People's Republic of China instead of the Nationalist government on Taiwan. Because the Soviet delegate was absent, no veto was cast, and the resolutions supporting South Korea passed.

8. Both crises began as popular protests encouraged by de-Stalinisation. In Poland, Moscow threatened force (Soviet troop movements and Khrushchev's flight to Warsaw on 19 October) but backed down. Khrushchev accepted Gomułka because Poland stayed communist, loyal to the Warsaw Pact and in control of its own unrest. In Hungary, Soviet troops intervened in Budapest on 24 October, failed to crush the rising and withdrew at the end of October. Nagy then allowed a multi-party system and announced withdrawal from the Warsaw Pact (1 November), so the USSR invaded in full on 4 November and installed Kádár. The difference shows the limit of Soviet tolerance: national variations were allowed, but not leaving the bloc or ending one-party rule.

9. Roosevelt, who had built a working relationship with Stalin, died in April 1945. Truman was more suspicious and openly critical of Soviet policy in Poland. Germany's surrender removed the common enemy. Soviet actions in Poland and Romania seemed to break the Declaration on Liberated Europe, and the abrupt cut in Lend-Lease angered Moscow. The successful US atomic test (July 1945) gave the USA confidence and made it less dependent on Soviet help against Japan. The best answers link these factors: for example, Truman's attitude and the bomb together made the USA more willing to take a firm line.

10. For 1949 as a turning point: NATO committed the USA to Europe's defence. The two German states made the division of Europe formal. Comecon was set up. The Soviet atomic bomb ended the US monopoly and began the arms race. The communist victory in China spread the conflict to Asia and led to NSC-68. Against: many of these events completed trends that started earlier, such as containment and the Marshall Plan in 1947 and the Berlin Blockade in 1948. The militarisation of containment came later, with the Korean War in 1950. Judgement: 1949 was a major turning point because the division of Europe became formal and the arms race began. This laid the basis for the militarisation that Korea completed, but it confirmed a split that 1947 had already made. Either judgement is acceptable if it is supported.

11. Orthodox historians (for example, Feis) blamed Soviet expansion and ideology, and saw US policy as a defensive reaction. Revisionists (for example, Williams and Alperovitz) placed much of the blame on the USA: its search for open markets, its use of atomic diplomacy and its failure to understand Soviet security needs. Revisionism began in the late 1950s, with New Left critics of US capitalism such as Williams (1959). It gained wide influence in the 1960s, when the Vietnam War made many Americans more critical of US foreign policy, and when new documents and a new generation of historians questioned the official account.

12. Agree: Korea was the first major war of the Cold War in which US forces fought directly, and the first to involve a UN force. It brought China into direct conflict with the USA and led to US protection of Taiwan. NSC-68 was put into practice, and US defence spending rose from about $13 billion (1950) to about $50 billion (1953). Containment became worldwide and military rather than mainly economic. Disagree: the conflict had already spread to Asia with the communist victory in China in 1949 and the division of Korea itself in 1945-48. The Truman Doctrine (1947) already promised worldwide support against communism. The war was also deliberately limited. Europe remained the central theatre: Germany and Berlin stayed the main flashpoints, and even Korea's biggest effects (NATO's integrated command, the debate on West German rearmament) were felt in Europe. Judgement: a well-supported answer might argue that Korea did not begin the globalisation of the Cold War, but it made it militarised and permanent. It changed the scale of the Cold War more than its geography.