Idealism as well as realism vied for greater pride of place in the 20th-century US theoretical perspectives on world politics. American foreign policy cyclically swung between idealism and realism. The idealistic mood prevailed in times of US prosperity and optimism following the end of the First World War. US President Woodrow Wilson is closely identified with the development of ideal thoughts in the United States. The idealistic mood, however, was repudiated and realistic assumptions dominated the US policymakers’ thinking after the Second World War.

Wilsonian Idealism 

It is argued that moral principles were dominant among US policymakers over the first four decades of the 20th century. The ingredients of idealism were put into practice during the Wilson presidency (1913-1921). In order to avoid another war, Wilson’s policy required that the world states relieve themselves of the balance of power and the pursuit of national interests. President Wilson put it himself that foreign policy should not be defined in “terms of material interest,” and should be “more concerned about human rights than about property rights.”

In addition to his idealistic ethical approach, Wilson’s vision of a peaceful world demanded the necessity of a democratic foundation. As a consequence, he put the promotion of democracy, to the emerging world order, at the centre of US foreign policy. President Wilson assumed that democratic states were more stable and peace-loving. Hence, they were the most suitable building blocks of the international system as long as they recognized each other’s legitimacy, Wilson contended. In this regard, Ikenberry argues that the promotion of democracy abroad, thus, dates back to Woodrow Wilson and the end of the First World War.

Furthermore, Wilson’s vision of a new world order recommended that democratically constituted governments should maintain peace through a system of a collective military security and liberal economic exchange, under a body of treatises that would assure equal access to world markets. For that reason, an international organization, the League of Nations, would be created.

Wilson’s idealistic framework for world order after the First World War called for the promotion of human rights and democracy, in addition to a system of collective security and a liberal economic regime. According to him, the conduct of foreign policy should be given a moral cast .

The Wilsonian agenda, however, seemed unable to create order after the end of the war.  This inability discredited Wilson’s idealism leading to its abandonment over the inter war years, and thus setting the stage for the introduction of realistic thinking in the conduct of US foreign policy.

Realism and Post-World War II US Foreign Policy

Realism, as an approach to US foreign policy decision making, vied for a pride of place by the time the United States of America emerged as a hegemonic power after the Second World War. The idealistic strand of thought did not completely vanish in US foreign policy, though. Ikenberry notices that there was a great debate between “an ascendant realism and a beleaguered idealism” in US foreign policy.

The realistic paradigm was brought into dominance by Hans Morgenthau for the study and conduct of post-World War II American foreign relations. Declaring that leaders “think and act in terms of interests defined as power,” Morgenthau sought to get the Americans rid of their belief in law, morality, and mutual interest as bases of world order. This line of thought was reflected in the Cold War policy of containment.

US Realistic Policy of Containment: From Theory into Practice
At the end of the Second World War, the international system evolved into a bipolar balance of power in which the United States and the Soviet Union emerged as leading powers. The two superpowers became rivals competing for power in a struggle in which the United States perceived itself as the forebear of what was right. The American perceived threat of Soviet expansion was considered dangerous to US national security. To do right was to bring Soviet expansion into an end.

In this context, George F. Kennan, the US State Department’s expert on the Soviet Union, established the basis of the US strategy of containment that prevailed in the Cold War era. Kennan’s policy depicted how the Truman administration should control the Soviet expansion. It was meant to limit and not permit the expansion of communism outside the borders of the Soviet Union territory.

Kennan believed that the Soviet Union did not pose a serious military problem to the United States since it was drained by the war. However, the Kremlin was “dealing in ideological concepts which [were] of a long-term validity,” Kennan wrote. Therefore, the United States had not to resort to the use of military power in a direct conflict with the Soviets. Instead, it should adopt a policy which, according to Kennan, had to be of a “longterm, patient, but firm and vigilant containment.”

Kennan’s containment strategy was accepted in Washington, whose leaders embarked on the task of translating its theory into initiatives. The containment strategy provided the foundation for subsequent doctrines that would define US foreign policy during the post-Second World War period. It found its first application in the Truman Doctrine.

The Truman Doctrine pledged economic aid as well as military supplies for European countries that were on the verge of economic destruction, political and social upheavals. Since the United States could not allow the expansion of the Soviet Union, US policymakers had to plan for a resolution in order to help Western Europe recover. For that reason, Secretary of State George Marshall called for the European Recovery Program, later known as the Marshall Plan (1948-1952).

Marshall demanded that the European states devise a plan for their economic recovery. The United States would supply their funds, but they had to do the planning themselves. The Economic Cooperation Act of 1948 called for the creation of an integrated European market. As time went by, European leaders anticipated a united Europe independent of American pressure. To this end, the European Economic Community was established in 1957, paving the way for political unification.

Not only was the Marshall Plan presented to war-torn nations in Western Europe, but it was also open to all European countries, including the Soviet Union. However, Stalin rejected the plan and refused to participate. His denunciation of the Marshall Plan resulted in the division of Europe into two blocs; one dependent on the United States, the other dependent on the Soviet Union.

Soon after the Marshall Plan was implemented, it was considered that economic measures would not suffice to roll the Soviet expansion back. The Soviet Union engineered a coup in Prague. It also challenged the post-war division of Germany. Therefore, it was clear that military security was necessary for Europe’s recovery. Thus in April 1949, the ten European countries, with the United States and Canada, created the North Atlantic Treaty Organization. NATO formalized the policy of containment in serving two functions. The first function was to counter the Soviet through a collective defense of NATO members against Soviet provocations. The second function was to defuse the European states’ rivalries by subordinating their military forces to the United States, the leader of the newly established alliance.