re: The U.S. government will let it happen.
"It just never ends, does it?" No it doesn't. This is a classic case of armchair foreign policy meeting the real world. A group of think-tank bozzos making decisions based on misconception and preconception discover that Iraqis, Afghans, Kurds, Turks, Iranians, etc. are not plastic toys on a cardboard game set, but real, independent political actors with their own agendas and goals, and who are, in many cases very adept at turning events to serve their own ends, not ours. What a surprise.