Attributed in Patton (motion picture) (1970). This is sometimes said to have been uttered in a speech by Patton to the Sixth Armored Division of the Third Army, 31 May 1944, but documentation is lacking. The following poem appeared in the Bureau of Aeronautics Navy Department News Letter, 1 Jan. 1943: "The greatest duty of a sailor / Is duty from worries and cares, / Not to die for his country, / Make our enemies die for theirs!"
Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.79, Skyhorse Publishing, Inc.