Answer: The CIA and the Marshall Plan.
By the end of WW2, most of Europe was devastated, along with its economy. With the Truman administration's announcement of the Marshall Plan in 1947, America stepped in to help Europe regain its footing.
The Soviet Union took an increasingly hostile view of the Marshall Plan, refused East Bloc participation and called it an "imperialist ploy" for the enslavement of Europe. Then, they founded the Communist Information Bureau which ordered party members to mobilize against the Marshall Plan.
Washington's increasing concern over the Soviet behaviour was one of several factors that led to the passage of the National Security Act of 1947, creating the Central Intelligence Agency (CIA).