Let's be honest. The United States has crossed the threshold on Iraq. We're in it to salvage the country — again — using American military might. But the mission has also, very quickly, grown much bigger in less than two weeks. U.S. warplanes are no longer simply helping create escape routes for the Yazidis or protecting American personnel in Irbil in Iraqi Kurdistan. The U.S. is now directly taking on the world's most militant extremist group, bombing its positions at the Mosul dam and beyond. And it's probably only the beginning.