There were at least three movies with this title, referencing the "War is Hell" quote by William Tecumseh Sherman. Presumably because you couldn't say "hell" in a cartoon, even two years before the Production Code began to be enforced.
Aside from some nice perspective work in the opening sequence -- as the mouse sentry is marching back and forth, the tents in neat rows in the background shift -- this is pretty much the same cartoon that its predecessors had been half a dozen years before, with its rubber-tube animation gags. Paul Terry showed spurts of ambition and he had a real staff at this time, but so long as he relied solely on director Frank Moser, and took all the writing credit himself, things were not going to change much.