What actions did the United States take to promote hegemonism in the early days after World War II?

1. Invite Churchill to visit the United States and deliver an iron curtain speech, releasing the cold war signal.

2. The Truman Doctrine was introduced, and the United States replaced Britain to fill the power vacuum in Greece and Turkey, marking the beginning of the Cold War between the United States and the Soviet Union.

3. Implement the Marshall Plan, provide economic assistance to Western Europe, promote the export of domestic goods in the United States, and economically control Western European countries.

4. Establish NATO, control the defense system in Western Europe, and strengthen the military threat to the Soviet Union.