sentences:  Truman laid the groundwork for his request by having key congressional leaders meet with himself, Secretary of State George Marshall, and Undersecretary of State Dean Acheson.Acheson laid out the "domino theory" in the starkest terms, comparing a communist state to a rotten apple that could spread its infection to an entire barrel.Vandenberg was impressed, and advised Truman to appear before Congress and "scare the hell out of the American people."