From 1946 – 1971 America tried to contain communist forces where USA intervened in the Korean War (1950 – 1953) and the Vietnam War (1964-1965). In both wars, USA tried to stop spread of communism from the North to South. USA’s view changed from trying to defeat communism, to containing it spread to other countries.
From 1972 – 1979 America’s foreign policy was détente which was a relaxed approach to world affairs, which started at the signing of the SALT I agreement, by USA and the USSR; which limited how many missiles each country could hold, thus reducing tension. USA had started to accept the existence of communist powers and how this would discourage another war, for America could use the time to recover from WWII.
Then was the period of the second cold war, 1979 – 1985. This was another period that was containment as the USA tried to contain the USSR’s invasion of Afghanistan, at which point the SALT II agreement was not ratified in 1979 due to this. USA’s views changed of communism as it was relaxed towards communism, but now, once again it was pursuing the need to contain communist spread. America had changed their view after the USSR’s decision to invade Afghanistan.
From 1990 – 2000, there was the Gulf war between 1990-1991. This was mainly between Kuwait and Iraq, but it was noted that America’s intervention was due to Kuwait’s oil supply. After the Gulf war, USA pursued for peace with the Middle East, especially Iran, who criticized America’s role in the Gulf war. USA changed its view as it would be easier to refrain from war, and achieve peace, than for another war to start and not having the money to rebuild their own economy.
The main causes of change were WWII which had changed the USA from Isolationist to Interventionist. This change had meant USA was involved in world affairs once again like the cash and carry system. Another main cause was the collapse of the Soviet Union in 1989 which was also the year the Berlin Wall fell, which was a main cause as America had ‘defeated’ their main rival. Through this time period, USA had realized that they were not able to defeat their enemies but the best they could do was to contain them and pursue for peace, as they did in the Détente stage. But to get détente, they have to get through the long period of containment where the pace of change was the slowest.