Movie Stars of World War II; How Hollywood joined the war and fought for freedom

World of Images  "Hollywood stars of the 1940s that put careers on hold to fight for freedom. Movie stars of World War II earned more than 300 medals and awards that honor their valor. U.S. awards and medals include Silver Stars, Distinguish Service Crosses, Air Medals, Bronze Stars, Presidential Unit Citations, Purple Hearts, and a Congressional Medal of Honor. "

One example from many:  Walter Brennan (1894-1974)

[The Long, Long Trail (1929); Sergeant York (1941); Smoke in the Wind (1975)]. In many ways the most successful and familiar character actor of American sound films and the only actor to date to win three Oscars for Best Supporting Actor, Walter Brennan attended college in Cambridge, Massachusetts, studying engineering. While in school he became interested in acting and performed in school plays. Brennan enlisted in the U.S. Army at age 22 to serve in World War I. He served in an artillery unit and although he got through the war without being wounded, his exposure to poison gas ruined his vocal chords, leaving him with the high-pitched voice texture that made him a natural for old man roles while still in his thirties. He was too old to serve in World War II.

How about this one about Mel Brooks:

Mel Brooks (1926- ) [Comedian, actor, producer and director, i.e, Blazing Saddles (1974)] served in the U.S. Army in WW II as a combat engineer and took part in the Battle of the Bulge. His main job was to deactivate land mines.
 

Of course you realize that Books, being Jewish, would have likely been murdered outright if he was captured by the Nazis.

Many more are listed here.  Hat tip to Paul Van Alstine.