In the 1948 film Key Largo
--at the beginning of the second act where Frank (Bogart) confronts Rocco (Edward G. Robinson) for the first time--Rocco pegs Frank for a soldier who fought in WWII and asks him why he "stuck his neck out"? Frank answers that he "believed some words" and then seems to quote a speech:
"But we aren't making all this sacrifice of human effort and lives to return to the kind of a world we had after the last world war. We're fighting to cleanse the world of ancient evils. Ancient ills. "
If we're to believe Lionel Barrymore's reaction, the speech was somewhat well-known--at least among soldiers/patriots of the time (no doubt the fact that Rocco sneered at it is supposed to be an overt confirmation of his villainy).
I guess this is probably from one of Roosevelt's wartime speeches, but I can't seem to find it anywhere other than in this movie. Anyone care to source it a little better before the hurricane hits?