I would venture to say the only war in the history of the US not worth fighting was the Spanish-American War. A lot of people might put Vietnam in that catergory, however, Vietnam was not a fight against even North Vietnam. It was one of the battlefields in the Cold War.
To ask which war we would stay out of, none of those countries listed had every last diplomatic angle tried, like Iraq had.
"I would venture to say the only war in the history of the US not worth fighting was the Spanish-American War..."
Not many people are aware of this, but we are still paying today a Telephone Luxury Tax that was instituted in 1898 to help fund that war.
Over the years there's been many efforts to repeal it, but it always keeps getting 'renewed'. So here we are in 2005, still PAYING a tax to fund a war from 1898.