In 1946 The McMahon Act was introduced , this was an act to end the US collaboration with Britain on the research and development of nuclear technology , and Britain's right of consultation over the use of any nuclear device. The Anglo-American relationship was still there, but just weakened, due to the change in relationship between America and Britain. In January 1947 Britain decided to build its own bomb because it was confused about whether or not there was still US commitment towards the defence of Europe as its defences were already weaker than the soviets .This all happened before NATO was established, therefore there were some doubts about their relationship .Britain was attempting to patch up their relationship with the US as they felt that their alliance was crippling , by signing an agreement in 1946 with the US that they were able to station their bombers in east Anglia in the UK, so that the US could protect Britain from any attacks. However by Britain agreeing to be the US' prime nuclear base, it was in danger of becoming a target of a retaliatory strike from the Soviet Union. Despite the attempt to re-establish the relationship , it didn't work as the American's discovered that there was a British scientist Klaus Fuchs that has been acting as a Soviet spy , which made the US more wary about sharing information , as Britain had nothing to offer the US ( bombs etc. ) . A US congressman pointed out that America 'would be exchanging a horse for a rabbit ‘, in other words it wasn’t worth sharing information with the UK because they didn't have anything to offer, even thought Britain tried hard to make itself worthy of their nuclear relationship again by creating an atomic bomb, but the US had already created their first thermonuclear device, the technology gap grew too much that there was no going back. Most of all the Anglo-American relationship was shown during the Korean War 1950-53 , as Britain proved the second largest amount of troops, to prevent Communist aggression in South Korea, this strengthened their relationship. An event that strained Anglo-American relations was the Suez Crisis in 1956 as America Criticized Britain’s actions. The relationship weakened because the US told Britain to withdraw their troops from the Suez and they did because it was very humiliating for them due to the fact that America was threatening to stop all aid if they didn’t, because they thought that the Suez ‘war’ was unjustified.
On the other hand the Anglo-soviet relationship was not at its best after World War 2 because the USSR no longer had the same goal of defeating Germany as they did before, that linked the 3 superpowers together.
After 1945 the USSR attempt to establish a Soviet bloc, which succeeded leaving only two countries in Eastern Europe (Czechoslovakia and Greece) not controlled by communist governments, therefore Britain and the US decided it was time to take action and they started to implement the containment policy. By 1946 the British policy hardened towards the Soviet Union as there was some tension over their positions in Iran, Greece and Germany. Britain started to feel threatened by the Soviet Union as the spread of communism was starting to expand elsewhere outside of Europe, in particular the Eastern Mediterranean where in Greece communists and Monarchists were competing for control after the Nazi withdrawal in 1945. It was important for Greece not to fall into communist hands as it was Britain's passage across towards the Suez Canal that provided access to the Middle East and it resources such as oil supplies. Earnest Bevin (labour foreign secretary) believed that if the USSR communised Greece it would harden Britain's position in the Middle East.
Furthermore, the threat of increased Soviet military made Bevin apply pressure to the Americans to take action as there was a threat of communist pincer movement around the Middle East, so the soviet troops withdrew in May 1946.
In 1953 when Stalin died a conference was held between leaders of major powers to discuss the future of the USSR. Churchill wanted to bring peace, however he died, but a summit did take place in Geneva in July 1955 by Eisenhower, Eden, the French premier, Faure and Khrushchev of the USSR. However due to the Suez Crisis and the soviet crushing of the Hungarian Uprising in 1956 the attitudes towards the Soviet Union did not improve. The Soviet Union threatened to attack Britain, Israel and France if it attempted to take over the Suez Canal. This demolished the relationship between them as the Soviet yet again didn’t side with Britain, but with Egypt.
The development of the Cold War was an attempt to introduce defence policies in the form of regional defence organisations around the world so that it would be able to contain the soviet threat. In 1949 they established NATO , 1951 ANZUS (Australia , New Zealand , US) and it was replaced by setting up SEATO (south East Asia Treaty Organisation) in 1954 and in 1951 they also established the MEC (another treaty for the middle East ) .It helped the British, as it meant that there were less overseas commitments. In 1963 the Soviets signed an arms reduction agreement, this was meant to create a better relationship with the Soviet Union and Britain and this was due to the talks that Macmillan and Khrushchev had after the death of Stalin. In addition in 1948 to 1949 the Berlin Blockade was another reason that created change in the Anglo-Soviet relationship as the soviet blocked all routes into Berlin in attempt to bring Berlin under Soviet control. The Blockade hardened the attitude toward the Soviet Union; therefore Britain didn’t really attempt to negotiate anything with the USSR in May 1949 when they held a conference with them.
Furthermore there was also a change in empire and decolonisation starting from 1947 with India. Britain was economically very weak after the war and had many commitments around the globe that it could no longer support, as it was no longer able to afford its military .Even though this was the case Britain could not let go of the Middle East that easily as it was an economic necessity due to its huge amount of oil supplies .Rapid decolonisation started in the 1960's particularly in Africa with 17 colonies gaining independence from 1960 to 1964.
Overall the British foreign policy changed in many ways as well as continuing their good relationship with America. It reached a conclusion of the fact that Britain’s policy changed immensely especially the Anglo-American relationship that changed overtime from being very strong to weaker. The area of most Continuity is the Anglo –soviet relationship as even though it changed numerous amounts of time, in the end they were still on bad terms.