You really need to look up the meaning of the word "help" the only people the US goverment helps are themselves , as for the world wars
Research the fucked up attempt to stage a landing (Omaha beach) in wwII
The war started in 39 not when the yanks could be bothered to drag their arses off the couch.
Then not content with that they get hollywood assholes stealing the thunder of other countries heroes (U571)