My answer was a careful consideration of limited use of land-based Airpower in concert with non-military instruments of national power. If land-based air is not available, do not further stress the Navy by going with sea-based options other than perhaps TLAMs.* Although I doubt that a few TLAMs here or there would save Erbil from a concerted offensive by Erbil's enemies.
Some on this thread evince a desire for a sort of clarity that I find has little to do with the real world.
That said, let us boil it down to several, fundamental questions:
-First, should the semi-autonomous regime in Erbil be threatened what should the US Role be? Military (first choice in all cases for last 30 years), Diplomatic (usually never employed alone and usually in back seat to military/hammer solution), economic, informational [thus I have used the DIME], other (this is for the HG audience to take on), or combinations?
I think we owe the Kurds a little more than just a debt of honor; there is a blood debt there as well. The United States highly encouraged revolts in Iraq following DESERT STORM, and then seem surprised when Iraqis and Kurds took them at their word. Kurdistan was a comparative bastion of stability during the dark days of occupation following IRAQI FREEDOM, and the peshmerga were among the most effective fighters against ISIS when the Iraqi Army was busy throwing its weapons down and running away.
Who wouldn't favor continuing our support for a de facto independent Kurdistan? And yes, they should accept de facto and not press too hard for total, recognized independence.
I remember Provide Comfort if only for the embarrassing lack of interservice coordination, which resulted in a USAF F-15 shooting down one of our own Blackhawk helicopters. Or was it two? Long ago, in a galaxy far away . . . As I recall, the fighter pilots were confused by seeing external fuel tanks on the helicopters, something always seen on Iraqi HINDs but seldom on US Army Blackhawks.