Psst, neither of you did anything, you're too young to have been involved in the second world war...although I know Zeus dates back to Ancient Greece, but that's beside the point.
But, bear in mind the victory in the second world war wasn't a victory you can thank a single nation for - I don't like the, "we saved your a** attitude", because America had their own reasons for joining, but to be fair, we wouldn't have won it without them, but hey, if so many countries didn't do their part, Nazi Germany would have been an even uglier force, hence we have more than one nation thank for it.
However, I don't think it's really an issue we can bring up with national identity, I mean, just because we live in the country and have a national identity, doesn't mean we actually 'did' anything, it was our grandparents and great grandparents.
To illustrate the point, Mitchell and Webb have just the sketch:
http://www.youtube.com/watch?v=xN1WN0YMWZU
Anyway, happy rub-it-in-England's face day! We will claim America back one day, you'll see!