It is a common Americanism to talk like we singlehandedly defeated the Nazis, as if no other nation really contributed. I've discussed it with a few foreign friends. I am not in any shape to discuss it intelligently at the moment. Just thought I would note that this egomaniacal hero complex is one of this nation's foibles.
I don't have some across the board policy, perhaps because friends have been scarce of late. Since basically no one speaks to me, I don't currently have any need to make judgement calls of that sort. But my personal history suggests I am disinclined towards sweeping judgements of any sort. (shrug)