Term: United States Secretary of Defense, Description: Leader of the United States armed forces following the president, Question: Did Barry Goldwater's successor serve in the military longer than the United States Secretary of Defense has?, Answer:Yes
Fact1: Barry Goldwater was succeeded by John McCain. Fact2: John McCain served in the military for 23 years. Fact3: The current US Secretary of Defense is Mark Esper. Fact4: Mark Esper served in the military for 21 years. 