American foreign policy during the Cold War was marked by both successes and failures, but if we consider the Cold War as a struggle for survival and power between two superpowers (and there are many other ways to think about it), then one would have to say American foreign policy...
American foreign policy during the Cold War was marked by both successes and failures, but if we consider the Cold War as a struggle for survival and power between two superpowers (and there are many other ways to think about it), then one would have to say American foreign policy was a very costly success.
The United States contained communist expansion into Europe in the two decades following the Second World War. This was through the joint strategies of collective security (through NATO) and economic aid in the immediate aftermath of the war (through the Marshall Plan). While there was little the US could do, short of waging war, to stop Soviet expansion into areas occupied by its army after WWII, American policies drew a line, as it were, around Eastern Europe. Similarly, the US stopped communist incursions into South Korea, this time through military intervention.
On the other hand, the United States botched its response to the Cuban Revolution, causing its leader Fidel Castro to turn to the USSR for support and to eventually establish a communist society. Years of bloody conflict in Vietnam ended with that nation's unification under the rule of the communist North. Moreover, the United States supported many tyrannical regimes because they were anti-communist, and opposed many democratic, left-leaning rulers. Some historians, for example, have argued that the United States helped to engineer a coup led by Augusto Pinochet in Chile. Pinochet would establish a bloody dictatorship in that country.
By another more basic measure, the Cold War was a success for the United States and the world in general. The US and the USSR managed to avoid nuclear conflict with each other throughout the period. Had they gone to war, the ensuing nuclear conflict would likely have destroyed much of humanity. So in this sense, too, American policy in the Cold War was a success.