Why did the US help the Kurds in Iraq but leave Isis to massacre them in Syria?

The Guardian ^ | 10/08/14 | Cale Salih

[arthurus]

Ultimately the Kurds are moslems. Their redeeming feature is that they are not all moslems and their Kurdishness is more important to them than their Islam. That makes them anathema to the orthodox Shia and Sunni. It is also the salvation of the Yazidi who are Kurds but most of whom adhere to the pre-moslem Kurdish religion that seems to derive from ancient Persian fire worship. It is also why Christians have found refuge among the Kurds. Some small part of the Kurds are Christians.

All in all that makes the Kurds quite an anomaly in the world of Islam. The Turks recently declared the Kurds in Turkiye to be Turkish citizens and have had diplomatic dealings with the non PKK (non Communist) Kurds in Iraq who have co-operated with the Turks in suppressing PKK in their areas in Turkiye and Iraq. I suspect they are allowing the Kobani Kurds to go down because they are PKK. PKK Kurds and their precommunist predecessors have been the thorn in the side of Turkiye for a century.