Look at Vietnam. We left and they're doing relatively great. We can't hope to bring Iraq back together. That's something only -they- can do, and by the looks of it, the iraqi people in general do not care enough to step up and do something great. We just need to leave because they do not have the heart to make a stable democracy. Being murdered and ruled is what they seem to favor.
Like I said, I'd rather we left but poured a bit of money into it.