The cold war started because the United States feared the Soviet Union was trying to control the world. There wasn't an actual war but there was lots of tension and fear of nuclear war.
Answer:
The Manhattan Project
Explanation: FDR started the project but was kept under secrecy so no other country would find out creating and testing nuclear weapons.
The Marshall Plan (officially the European Recovery Program, ERP) was an American initiative to aid Western Europe, in which the United States gave over $12 billion (nearly $100 billion in 2016 US dollars) in economic assistance to help rebuild Western European economies after the end of World War II.
I believe the answer is the first one
