Support Kurdish nationhood abandon Shiites to Iran and Sunnis to Turkey

As Islamic State Withers, The Alliance Against it is Fraying which is as you would expect with 'your enemy is my enemy' accords where the old enemy is diminished making previous antagonisms apparent.  This article makes the statement that Iran and its allies  have the upper hand, as if that wrapped up the debate about working with Iran to further pacify the region.  Iran is tolerant of the Kurdish so that their nationhood in parts of Iraq and Syria is viable as long as American support for Kurdistan is economic. Otherwise abandon the rest of it leaving Sunnis to Turkey and Shias to Iran to more or less dominate.