"[Truman's] fateful decision to send U.S. planes and ships into the Korean fighting was made with advice of Representative Walter Judd (1898 - 1994: R., Minn.). Judd had been sharply critical of U.S. Far Eastern policy on grounds that it was opening the door to Communism. The day after fighting started, State Department officials asked Judd's advice on procedures for helping South Korea...[The State Department], looking for a method of routing immediate aid without by-passing the U.N., accepted Judd's plan and sold it to President Truman."
President Truman did not commit American troops to the war without considerable thought, he was one of the few U.S. presidents of the 20th Century to have seen combat. The photo above shows Truman in W.W. I France, where he served as an artillery officer.
Click here to read more about the Korean War.
What was the Truman Doctrine?