Gerrold, David. "The Firebringers"
What if: Various Hollywood stars were in real life the types of men they played in the movies.
Summary: Commanding a bomber carrying a nuclear device to Berlin, Col. Gregory Peck has second thoughts, and argues with Reagan, Bogart, et al.
Published: In Alternate Warriors (ed. Mike Resnick), q.v.; and Alternate Gerrolds, q.v.