This post makes a great point: if the US, allegedly, has the "greatest military in the world", why have we lost THREE (count 'em 1.2.3.) wars in a row? Here, I am thinking Korea, Vietnam, and now Iraq 2. Really, can you honestly answer the question? The point is, I think, you either have to be in for amoral, wholesale slaughter or you are in for a loss.
A determined, insurgent force can fuck you up.
And our troops are paying the price for the stupidity of the ruling elite.