Korean War and US Containment Policy

As World War II came to an end, a series of diplomatic, military, and ideological clashes between the United States and the Soviet Union began to take shape. These early encounters not only solidified the divide between capitalism and communism but also set the stage for the prolonged period of tension known as the Cold War. One of the pivotal events signaling this division was the establishment of certain policies and actions that defined the approach of both superpowers. Among these was the American policy of containment, aimed at preventing the spread of communism beyond its already existing borders.

Which of the following events exemplifies the United States' shift towards a policy of containment in the early years of the Cold War?