Johnson Out, General C. Marshall In The former chief of staff and one-time state secretary, George C. Marshall, takes over as defense chief following the resignation of Louis Johnson. New task for an old soldier. George C. Marshall acted as a diplomat as Secretary of State from 1947 to 1949, and helped formulate the Marshall Plan. For one year during the Korean War, General Marshall was Secretary of Defense. A civilian post in the US Cabinet. MCU of General Marshall walking up the steps in his civilian cloths. MCU of General Marshall sitting at his desk. CU of Secretary of Defense, General George C Marshall.