Why can't airstrikes give anti-Isis fighters an overwhelming advantage?

Negotiations failed when Iran laid down the law and pulled the strings necessary to allow Iraq to successfully form a government, which was conditional on Iraq not renegotiating a SOFA with the US that would allow troops to stay.

My guess is that the US is really only able to provide precision strikes on well-defined targets which would mean obvious concentrations of troops or equipment or structures. There’s no forward air controllers or spotters to provide tactical support against “hot” enemy positions plus I doubt we’re flying the kinds of planes or at ranges where they can provide low-level air support with weapons like 30mm cannon. Definitely no helicopter support.

I think recently they’ve managed some coordination between ground and air allowing for limited tactical abiiity – maybe providing them with IR laser illuminators that can ID a target for a plane overhead to target, so at least they bomb something an active part of the battle.

The enemy in this case is well organized but still a largely irregular force fighting in a semi-organized guerilla fashion, blending easily into the civilian infrastructure and probably willfully using residential and civilian facilities as cover.

Viet Nam showed the effectiveness of using strategic air assets (big bombers dumping massive payloads) against tactical targets but you have to be willing to accept the bad with the good. We could carpet-bomb ISIS occupied parts of Kobani and probably end the siege, but that part of Kobani would be a rubble field afterward with everything, including civilians, destroyed.

Watch any decent documentary footage of Khe Sanh – at the beginning of the seige, the area around Khe Sanh is a lush forest. After the siege, the the B-52 “Arclight” srikes used against the NVA left the area a defoliated moonscape. The headlines would read “Indiscriminate US attacks defeat ISIS, leave humanitarian refugee crisis by reducing city to rubble”.

How many more decades do you think we should stay in Iraq?

I don’t care. We have technically never left Germany.