Kerry proposes to continue war against PISSI for years, but there is no reason to think such a war could ever be won.

I think this is part of a plan to slowly send a large number of US troops to fight PISSI on the ground.

Attrition, and death of some leaders, can't defeat PISSI. Land battles can push PISSI back, but doing this with US troops would not work because their occupation would inspire the same resentment as before.

It is impossible to defeat PISSI except by giving Iraqi and Syrian Sunnis a way to be safe from Shi'ite repression. If they get this, they may well throw PISSI out. However, the current repressive behavior of Iraqi Shi'ite militias surely convince them to they must keep supporting PISSI