Can a military person defend themselves while training on a US base here on the USA??

Regardless of what branch of the military, everyone has the same set of rules. Unless this "person" has threatened this Marine, and he's used all other means to stop this person (shout, shove, show, shoot [not to kill]) then yes, he can. But I'm sure that a Marine can detain this person and call the MPs...And yes, we are held to different standards...HIGHER standards. We aren't just killing machines, or barberic animals...ya know.