What effect did World War II have on our foreign policy?

WWII saw the end of the Isolationist tradition in the United States, it had been reintroduced between the two World Wars. Isolationism had been the rule in foreign policy until the very end of the 19th century and the invasion of the Philippines.

World War II significantly altered United States foreign policy by shifting its focus towards international involvement and leadership. The war led to the emergence of the United States as a superpower, resulting in increased involvement in global affairs, the establishment of international institutions such as the United Nations, and the implementation of policies aimed at containing the spread of communism, such as the Truman Doctrine and the Marshall Plan. Additionally, World War II led to the beginning of the Cold War, shaping U.S. foreign policy in terms of containing Soviet influence and promoting democracy and capitalism worldwide.