The Yalta conference was the beginning of the cold war when the big three sat down and talked about what their plan to do with Gremany

these three events all happened in the same year the first was the bombing of pearl harbor then , Russia declaring war with japan finally the surrender of japan

The Truman Doctrine was an American foreign policy whose stated purpose was to counter Soviet geopolitical expansion during the Cold War. It was announced to Congress by President Harry S. Truman on March 12, 1947, and further developed on July 12, 1948, when he pledged to contain threats in Greece and Turkey.

The Marshall Plan was an American initiative passed in 1948 to aid Western Europe, in which the United States gave over $12 billion in economic assistance to help rebuild Western European economies after the end of World War II.