The American mindset is such that even faced with overwhelming odds, the American is likely to say something more along the lines of "We'll win against all odds or die trying". It's a mindset that does not assume or accept defeat but recognizes that it is a possible outcome.

It has less to do with winning or losing wars (completely irrelevant) and far more to do with the way that the nation developed. Americans expanded westward on the basis of a generally optimistic outlook coupled with a willingness to struggle to make something. The people who came over here frequently had only the clothes on their backs, but were able, due to the opportunity of America, to become fabulously wealthy. Not everyone did, but that is the spirit and the basis of the nation.

As a result, Americans don't like heavy investment in social programs. Give everyone the opportunity and let people succeed or fail on their own merits. It's worked for almost 250 years.

As an aside, the South didn't "lose" in the mindset of Americans. It was "temporarily subdued", but "The South will rise again!" is a popular saying in the South to this day. No one has been defeated and the fight hasn't been forgotten. At least, that's the idea behind the saying.

I find this unwillingness to accept defeat an endearing and positive quality that will help keep America competitive even if China becomes a new superpower.

As for the Tolkien battle cry, it is a very nice Nordic sentiment along the lines of "Valhalla!" and I think a lot of Americans can appreciate the romantic, Wagnerian undertones of such a battle cry (without ever contemplating using it in a similar situation). The fact that one American does not understand it should not be imputed to the entirety of our great nation.