James Clapper started out as Marine.
After a brief enlistment in the United States Marine Corps Reserve, where Clapper served as a rifleman and attended the junior course of Platoon Leader Training he transferred to the U.S. Air Force Reserve Officer Training Corps program.[11][14][15] In 1963, he graduated as a distinguished military graduate from the University of Maryland and was commissioned as an Air Force second lieutenant.
https:// en.wikipedia.org/wiki/James_Clapper