who wrote war machine

The answer depends on which “War Machine” you mean:

• The Marvel Comics character War Machine (James “Rhodey” Rhodes) was created by David Michelinie, John Byrne, and Bob Layton as a supporting character in Iron Man comics.

• The 2017 satirical war film “War Machine” (starring Brad Pitt) was written and directed by David Michôd , inspired by Michael Hastings’ nonfiction book The Operators.

If you tell me whether you meant the comic character or the 2017 movie, I can give a bit more detail around publication/production and context. Information gathered from public forums or data available on the internet and portrayed here.