Me too.

The climax of Shaun of the Dead ends with the surviving main characters rescued by the British Army.

The film version of The Mist has the U.S. Army fighting back the monsters that arrived with the titular mist... but they're too late to save the main characters. Similarly, the monster in Cloverfield is indeed eventually taken down by the U.S. military as well - offscreen, after the fate of the main characters has already been determined.

And Lord of the Flies, of all things, also ends with the children being found and rescued just as things are at their worst... by, ironically enough, a military pilot who soon goes back to fighting a war.