U.S. senator from New Hampshire (1937–61), a leader of the conservative wing of the Republican Party, became controversial for criticizing the policies of Pres. Harry S. Truman (Truman, Harry S.)'s second administration (1949–53). He attacked Secretary of State Dean Acheson (Acheson, Dean)'s foreign policy, which resulted in U.S. entry (1950) into the Korean War; Truman's dismissal (1951) of Gen. Douglas MacArthur, commander of United Nations (primarily U.S.) forces in Korea; and the President's seizure of steel mills during an industry-wide strike (1952).