Lend Lease was a vital agreement that underpinned Britain's finances during the war. It specified that the US would supply Britain with war material in return for military bases. After the Second World War the US cancelled the lease and Britain faced financial disaster. Although America rescued Britain's finances again with another loan in 1946, it used the loan terms to achieve its own economic ends. In 1947 Britain suffered another financial crisis, the clause from the loan agreement forcing it to make sterling freely convertible into dollars. The poor economic situation and increasing US fears about communist gains in Western Europe led to the Marshall Plan; it provided assistance to many countries, but the USSR prevented Soviet-occupied regions from taking any of the money.
During the late 1940s America became increasingly worried about communism and looked to Britain to take the lead. Britain did not want to become isolated in Europe and wanted to ensure the US remained committed to European security. Britain played a big part in coordinating the establishment of the Western Defence Union and its enlargement into the North Atlantic Treaty Organisation (NATO).
In 1947 the US announced the Truman Doctrine, giving economic and military aid to Greece and Turkey to defend against communism. The British Foreign Secretary, Ernest Bevin, considered the Soviet Union to be Britain's prime enemy and felt the need for a concerted Western European defence. The US encouraged Britain to broker the Brussels Treaty of March 1948 with this as a premise.
The 1948 Berlin Blockade strengthened Anglo-American collaboration and in 1949 the US joined the North Atlantic Treaty Organisation (NATO). From July 1948, the US B29 bombers, capable of delivering atomic weapons, were stationed in East Anglia, Britain. Furthermore, Britain and the US made a number of bilateral military agreements called the Burns-Templer Agreements between 1948 and 1950. These alliances and arrangements meant that Britain was at the forefront of a war between the US and the Soviet Union. However, Anglo-American attention soon moved away from Europe to the Middle and Far East.
Britain's changing relationship with Europe (combined with its changing imperial position) led to changes in Anglo-American relations. The Cuban Missile Crisis of 1962 indicated the increasingly peripheral role of Britain as a superpower. Major decisions that had great significance for Western Europe were essentially taken by the US. Harold Macmillan's success in his pursuit of Anglo-American 'interdependence' was mixed, and successive British governments in the 1960s and 1970s pursued a close but not "interdependent" relationship. From 1973 Britain's new membership of the European Economic Community (EEC) meant it soon became a bridge between Europe and the US. The US increasingly saw Britain as a European state than a global partner.