And he went. And learned from that experience.
Imagine, an actor with real combat experience. I can think of only one...Dennis Franz from NYPD Blue.
Dale Dye, R. Lee Ermey (both Vietnam), Charles Bronson, Henry Fonda, Eddie Albert, Ernest Borgnine, Jimmy Stewart, Charles Durning (WWII) to name just eight and there are dozens more.
Not really an actor, but Oliver Stone is a Vietnam Vet.
Quoting from Wiki, he "was wounded twice in action. His personal awards include the Bronze Star with "V" device for valor for "extraordinary acts of courage under fire", and the Purple Heart with one Oak Leaf Cluster."