International Relations, 1945–60 (AQA A-Level History): Revision Notes
Development of the Cold War, 1945-51
Introduction
Following the Second World War, the USA underwent a substantial shift in foreign policy. The nation moved away from its traditional stance of isolation towards active engagement in global affairs, particularly focused on the containment of Communism in Europe and Asia. By 1945, the USA held a monopoly on nuclear weapons, but this advantage would not last the decade. Whilst initial concerns centred on Soviet expansion into Eastern Europe, by 1950 it became clear that Communism posed a worldwide challenge. The fall of China to Communist forces in 1949 and the outbreak of war in Korea in 1950 confirmed that the USA needed to commit to a global strategy of containment.
This period marked a fundamental transformation in American foreign policy, ending over a century of isolationist tradition and establishing the USA as a global superpower committed to preventing Communist expansion worldwide.
Post-war relations and the breakdown of the wartime alliance
The wartime context
During the Second World War, the USA and USSR formed an uneasy alliance against their common enemy, Nazi Germany. Once that shared threat was defeated, fundamental differences between the two superpowers quickly emerged. The USSR had endured catastrophic losses during the conflict: possibly 27 million dead, 25 million left homeless, and 6 million buildings destroyed. Nazi Germany, with whom the USSR had held a non-aggression treaty, had invaded without warning. Nine of the USSR's fifteen republics had experienced direct fighting during the war.
Understanding the Soviet perspective
The scale of Soviet suffering during World War II is difficult to comprehend. These losses represented approximately 14% of the Soviet population, compared to less than 0.3% for the United States. This enormous disparity in wartime experience would fundamentally shape post-war attitudes and negotiations between the two superpowers.
Soviet security concerns and expansion
Buffer zone: A protective area of friendly or controlled territory surrounding a country, designed to provide security against potential invasion.
Stalin argued that the USSR's immense suffering justified its demand for security guarantees. The Soviet leader was determined to ensure his country could not be attacked without warning again. The most effective way to achieve this security was to control neighbouring states, creating a buffer zone between the USSR and the rest of Europe. By invading Eastern European countries such as Poland during the final stages of the war, the USSR demonstrated its intention to maintain substantial influence over these territories in the future.
The Yalta Conference, February 1945
Allied leaders met towards the end of the war to plan post-war arrangements. At Yalta in February 1945, President Roosevelt appeared notably ill and seemed inclined to sympathise with Stalin's position. Several important agreements were reached:
- Germany would be divided into occupation zones
- Germany would be forced to pay war reparations, with half going to the USSR
- The USSR would gain territory from Poland
- Poland would be compensated with land taken from Germany
These arrangements appeared to give Stalin much of what he wanted, effectively securing Soviet dominance in Eastern Europe.
Truman's succession and changing American attitudes
In April 1945, Roosevelt died. His successor, Harry S. Truman, adopted a more critical stance towards Stalin. Unlike Roosevelt and Churchill, Truman had not experienced direct cooperation with Stalin in defeating the common enemy. The USA had not suffered during the war in any way comparable to the USSR, enduring less than two per cent of the Soviet Union's human losses. Roosevelt had taken this disparity into account when responding to Soviet demands; Truman did not share this consideration.
The change in American leadership from Roosevelt to Truman marked a crucial turning point in US-Soviet relations. Truman's lack of wartime cooperation experience with Stalin and his more confrontational approach would set the tone for escalating Cold War tensions.
The Potsdam Conference, July 1945
The next meeting of the Allied leaders took place at Potsdam in July. Britain also had a new leader by this point, though the Yalta agreements were confirmed. An extensive poll revealed that 50 per cent of Americans still believed wartime cooperation between the two superpowers should continue, suggesting public opinion had not yet fully turned against the USSR.
Soviet imposition of Communist regimes
By this time, Stalin was proceeding to install Communist regimes in many countries that had been 'liberated' from Nazi influence or occupied by Soviet forces. In Romania, for instance, at a meeting with the Soviet deputy foreign minister, the King was given just two hours to introduce a pro-Communist government. Whilst Truman was clearly troubled by this forcing of Communism upon Eastern European countries, he could do little about territories where Soviet armies of occupation remained. However, he grew increasingly concerned that Communism should not spread to countries not currently under Soviet control.
The emergence of Cold War tensions, 1946-48
The Iron Curtain speech, 1946
Iron Curtain: An imaginary border between Communist and non-Communist territories. The term refers to the political, military and ideological barrier established by the Soviet Union after the Second World War, with 'iron' emphasising the strength and impermeability of this division.
To Truman, it appeared that the USSR was seeking not merely to protect its borders from future invasion, but rather to control the whole of Europe. In 1946, Winston Churchill, visiting Fulton, Missouri, spoke of an Iron Curtain descending through the middle of Europe. This metaphor seemed even more appropriate when the Soviets forced Czechoslovakia to adopt Communism in 1948. By this point, Romania, Poland, Hungary, Bulgaria and Yugoslavia were all governed by Communist administrations. Only Greece, where a civil war was taking place between Communist and non-Communist forces, held out against Soviet dominance in Eastern Europe.
Cold War: A state of confrontation between nations that stops short of actual direct military conflict.
People began to speak of a state of Cold War that had developed between the USA and USSR. This term captured the reality of deep hostility and competition without open warfare between the superpowers.
The Truman Doctrine, 1947
Truman Doctrine: The policy announced by President Truman in 1947 offering American support to countries struggling against Communism.
In 1947, Truman formally offered the support of the USA to countries struggling against Communism. In a speech, Truman declared:
'I believe that it must be the policy of the United States to support peoples who resist being enslaved by armed minorities or by outside pressure. I believe that we must help free peoples to work out their own destiny in their own way.'
Containment: The strategy of preventing the spread of Communism to new territories, whilst accepting its existence where already established.
This policy became known as the Truman Doctrine or containment, as it appeared to commit the USA to stemming the spread of Communism. The doctrine was first applied in Greece, where aid was provided to non-Communist forces. Greece did not become Communist, and the first intervention appeared successful.
Marshall Aid, 1947-48
Marshall Aid: American economic assistance programme providing $13 billion to help European countries recover from the effects of the Second World War.
In the year following the announcement of the Truman Doctrine, the USA went further by offering a $13 billion package to help European countries recover from the effects of the Second World War. This programme was named Marshall Aid, after the US Secretary of State, General George Marshall. A conference of 22 nations was established to assess the economic needs of affected countries.
The USSR chose not to attend this conference and refused permission for countries under its sphere of influence to participate. Eventually, sixteen Western European nations formed the Organisation of European Economic Cooperation (OEEC) to administer this funding. The aid was designed partly to help countries recover their prosperity so that Communism would lose its appeal to impoverished populations. The programme successfully helped Western European countries to recover economically, and fears of Communist takeover in countries such as Italy and France receded.
However, in the years that followed, two serious crises emerged in which direct confrontation between the USA and USSR seemed probable.
The Berlin Airlift, 1948-49
The division of Germany and Berlin
Following the end of the war, Germany had been divided into four zones of occupation. The capital, Berlin, was also divided into four sectors, though it physically lay deep within the Soviet zone of occupation. The Western occupying powers—the USA, Britain and France—relied on Soviet goodwill to travel through the Soviet zone to reach their sectors in Berlin.
By 1948, it became clear that the three Western sectors were cooperating effectively and recovery was progressing well through the implementation of Marshall Aid. In contrast, the Soviet zone remained impoverished, and Communism was being imposed upon it.
The currency crisis and Soviet blockade
In June 1948, the Western zones introduced a new common currency, the Deutschmark. When Western leaders attempted to introduce this currency into their sectors of Berlin, Stalin ordered all transport links with the West to be cut. He believed he could blockade Berlin into accepting Communist rule and thereby make the capital part of a future Communist East German state.
The Allied response
In response, Britain and the USA organised an airlift of essential supplies to supply the city under siege. By March 1949, 8,000 tons of supplies per day were being delivered, despite Soviet threats to the aircraft, which were naturally flying through Communist-controlled airspace. On 9 May, Stalin called off the blockade and conditions returned to normal.
Significance of the Berlin Airlift
The Berlin Airlift represented the first major confrontation of the Cold War, and the USA had achieved a clear success. This demonstrated that the Western powers could respond effectively to Soviet pressure without resorting to military conflict, establishing a pattern for Cold War confrontations.
In a speech in 1949, Truman reflected:
'We refused to be forced out of the city of Berlin. We demonstrated to the people of Europe that we would act and act resolutely, when their freedom was threatened. Politically it brought the people of western Europe closer to us. The Berlin blockade was a move to test our ability and our will to resist.'
Contrasting interpretations
Contrasting Perspectives: The Berlin Crisis
American Perspective (Truman, 1949): The USA successfully defended West Berlin through determination and resolve, demonstrating American commitment to European freedom and strengthening Western unity.
Soviet Perspective (1977 Soviet account): 'The crisis was planned in Washington behind a smokescreen of anti-Soviet propaganda. In 1948 there was danger of war. The conduct of the western powers risked bloody incidents. The self-defence of the western powers hit the West Berlin population with harshness. The people were freezing and starving. In the Spring of 1949 the USA was forced to yield. Their war plans had come to nothing, because of the conduct of the Soviet Union.'
These contrasting accounts demonstrate how the same events were interpreted through entirely different ideological perspectives.
The formation of NATO, 1949
NATO (North Atlantic Treaty Organization): A defensive military alliance formed in April 1949, with members including the United States, Britain, France, Luxembourg, Holland, Belgium, Canada, Portugal, Italy, Norway, Denmark and Iceland.
The Berlin Crisis confirmed Truman's commitment to the policy of containment in Europe and highlighted the Soviet threat to Western European nations. Western European states, even when joined together, were no match for the military power of the Soviet Union and needed the formal support of the USA. In April 1949, the North Atlantic Treaty Organization (NATO) was signed. Although described as a defensive alliance, its main purpose was to prevent Soviet expansion.
The member countries agreed that an armed attack against one or more of them in Europe or North America would be considered an attack against them all. This collective security arrangement meant that Soviet aggression against any NATO member would trigger American military involvement.
NATO's formation represented the formalization of American military commitment to Europe, transforming the Truman Doctrine from a policy statement into a binding treaty obligation. This marked the complete abandonment of American isolationism and established the foundation for Western Cold War strategy.
The Korean War, 1950-53
Background and division
Korea is a country in Asia that shares borders with both the USSR and China. Following the Second World War, it was divided into North and South at the 38th parallel (a line of latitude). Whilst the government of the South supported the USA, the regime in the North was Communist and hostile to American interests.
North Korean invasion and UN response
In March 1950, North Korea invaded South Korea. The United Nations sent forces to halt this invasion; the vast majority of these troops were American, serving under an American Commander, General Douglas MacArthur. UN forces succeeded in liberating South Korea from Communist occupation.
MacArthur's controversial strategy
However, on MacArthur's urging, UN forces then proceeded to invade North Korea, ignoring explicit warnings from China about the consequences. President Truman faced tremendous hostility within the USA when he dismissed MacArthur for exceeding his instructions. To many Americans, it seemed Truman was being soft on Communism. Some believed UN troops should have finished off North Korea entirely and then invaded China itself to reverse the Communist threat completely.
Chinese intervention and stalemate
China became directly involved in the conflict, dispatching thousands of troops to assist the North Koreans. The war effectively became a stalemate that lasted for three years. The USA alone lost 27,000 troops, and one million Korean civilians died. In 1953, a peace agreement of sorts was reached in which Korea remained divided into a Communist North and non-Communist South.
It is now known that the Soviets secretly sent air forces to help the North Koreans. Had this been known at the time, the consequences could have been profound, with the confrontation between the USA and USSR possibly spreading to Europe.
The results and consequences of the Korean War
Domino theory: The belief that if one state fell to Communism, it would be quickly followed by neighbouring states falling like a line of dominoes.
The USA learned from Korea that Communism represented a global issue, and if they were to prevent its spread, then a global commitment was necessary. In the early 1950s, President Eisenhower spoke of the domino theory. Whilst this policy may appear overly simplistic, it was nevertheless a deeply held view and was later used to justify full-scale American involvement in the Vietnam War.
In its second phase, the war had effectively been a Sino-American conflict. Sino-American hostility was greatly increased by the war, and the United States provided increased support to Taiwan. The conflict helped to sustain McCarthyism and generally worsened Cold War antagonism.
Key Lesson: Limits of Containment
However, the three leading powers demonstrated that they were unwilling to risk a Third World War. The dismissal of MacArthur signalled that America planned to adhere to the policy of containment rather than attempting to roll back Communism through direct military confrontation with major Communist powers.
Key dates: the development of the Cold War, 1945-51
Timeline of Key Events
- 1945: Yalta Conference (February); Truman becomes President (April); Potsdam Conference (July)
- 1946: Churchill's Iron Curtain speech at Fulton, Missouri
- 1947: Truman Doctrine announced; Marshall Plan initiated
- 1948: Czechoslovakia forced to adopt Communism; Berlin Crisis begins (June); Berlin Airlift commences
- 1949: Berlin blockade ends (May); NATO established (April)
- 1950: Korean War breaks out (March)
- 1951: Truman dismisses MacArthur
Remember!
Key Points to Remember:
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The wartime alliance between the USA and USSR broke down rapidly after 1945 due to fundamental differences over security and ideology. Stalin's imposition of Communist regimes in Eastern Europe directly conflicted with American principles of self-determination.
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The Truman Doctrine (1947) and Marshall Aid (1947-48) represented the twin pillars of American containment policy: political support and economic assistance to countries resisting Communism. This marked a decisive break from pre-war American isolationism.
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The Berlin Airlift (1948-49) was the first major Cold War confrontation, demonstrating American resolve to resist Soviet expansion in Europe. The successful airlift, delivering 8,000 tons of supplies daily by March 1949, forced Stalin to back down without direct military conflict.
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NATO's formation in April 1949 formalised American military commitment to Western European defence, establishing the principle that an attack on one member would be considered an attack on all.
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The Korean War (1950-53) confirmed that the Cold War was a global struggle, not merely a European one. The dismissal of MacArthur and the eventual stalemate demonstrated that the USA would pursue containment rather than attempting to roll back Communism through total war, as the superpowers were unwilling to risk a Third World War.