[calibraxis]

The US could simply let the Kurds in northern Syria wipe out ISIS. They have the track record as the world's best ground force against ISIS.

But Turkey, the ISIS-friendly NATO partner that's bombing its own cities, wants to obliterate them. It does everything it can to keep the Kurds from closing the Turkey-ISIS supply line. Turkey's government is such an embarrassment that "Obama now considers [Erdoğan] a failure and an authoritarian." (http://www.theatlantic.com/magazine/archive/2016/04/the-obam...)

The US government can easily end ISIS. But they have other priorities and agendas too. They want certain outcomes.