The real reason is we don’t care enough. Why would we value you and your family less? It is a hard thing to say to you, though I have no doubt you know it in your heart. Europe was not only the home of most of our ancestors, the source of the intellectual, philosophical and spiritual traditions which guided us, but it is familiar and comforting to us as well. You, however, are far more culturally, spiritually and historically divorced from us, or at least we believe that to be true. You are the other, Europe is related. I have written of the way we tend to view these things, and it is human nature. Some of us see the gap between our caring for our family, country, and countries we are more familiar with, in descending importance, as smaller than others do. I cannot honestly say I don’t feel to some extent the same way, but the difference isn’t as large as it is for most Americans or Europeans apparently. Iraq was fine when it was thought (foolishly) that it would be quick and easy. Unfortunately Americans are not willing to spend 1/20th of what we would to save Europe in resources, and we are not willing to spend 1/1000th of what we would in casualties, for Iraq. That is the cold hard truth.
I tried to have this conversation with a blogger here in America who is one of the most extreme in her desire for withdrawal. I presented a situation quite analogous to the Middle East, but placed the issue in Europe. In that circumstance she was more than willing to say she would support our involvement. When I pointed out that that was exactly the situation we faced in the Middle East, she abandoned the conversation. She didn’t want to face the implications of it, but we all know it is true.
I don't agree with 100% of this, but it is a detailed, intelligent response well worth the read.