Well, it's all been said really; however, why do people keep mentioning the American help in the war, and how Europeans should be eternally grateful? (especially when they weren't even in the wars themselves).
1) I was not involved in WW1/2. I have nothing to be grateful to the US for, in that context.
2) People should be free to criticise the US, whether that be justified or not; Americans in particular seem to find that too bitter a pill to swallow.
3) I don't think I need to say this, but to avoid knee-jerk reactionists-I am most certainly not "anti-American".
4) I don't think some French people hate the US because they feel ashamed to admit help from previous wars.
I am led to beleive that Parisians, in general, have to put up with a constant flow of tourists-and after a while it can conceivably become frustrating to have so many noisy strangers around 24/365.
The cultural animosity between France & the UK or US, if you accept that there may be such feelings, is most likely to do with cultural differences, and France's culture perceived as being under threat from "uncivilised" influences (Mcdonald's, whatever).
Just my personal thoughts.
Oh, and no, we must never go to war with the French. We have a lot to thank them for.
Paris is simply THE city. Intellectual, elegant, smart & very civilised. And the food.....