" Iraq was decimating the Kurds through use of air power. The operation you describe sterilised that air power."

The Kurds were being attacked by both the Iraqi Air Force and by the Iraqi Army.

"ISIS is not decimating (or worse) the Yazidi through air power but through land power."

Ah so that's alright is it? They are not decimating those they have trapped they are intent on slaughtering every last one of them. Yet as others have said not one yelp of objection can be heard above the roar of "Save Gaza, save Gaza".

"So how do you think the Iraqi forces can resist that land power? The last rumble between Isis and them ended, did it not, with the Iraqi's abandoning their weapons and running away?"

The Iraqi Army and the Shia Militias will do it, might take time but they will do it. The last time? Well they were for the most part Police and Border Police Units with some Army units - I note the ISIS "drive" on Baghdad has halted? Changed their minds have they? Or has something else changed it for them?   

"Israel could be stopped by cutting off arms sales to it and cutting off the massive US subsidy."

Possibly could but we both know that that is not going to happen don't we?

"Isis? Last I heard the assets they seized made them richer than the rest of Iraq. OK, maybe I exaggerate, but how far off is it?   They are apparently not susceptible to financial pressure, only military."

And what good are those assets? Can they produce oil? Can they transport it to any loading terminal? Can they sell it? Rhetorical question Richard the answer to all is a big NO, so those assets are of no use to them whatsoever.

"Similarly apparently Boko Haram outguns the Nigerian army (and like the Viet Cong hides in dense forest)."

Early days yet for that bunch, but their time is coming, their métier is destruction - they have no future.

"Israel may (although resistant) be susceptible to western outcries. ISIS or Boko Haram - you must be joking!"

Israel when it comes to matters that impinge upon its sovereignty and upon its security is pretty much inured to the outcries of anyone else. They will remorselessly do whatever needs to be done - They showed that to be the case in 1967 in the face of what seemed invincible odds and they are perfectly capable of doing so again. ISIS or Boko Haram will collapse from within if left long enough to stew, they are essentially bandits and will ultimately be dealt with as such, neither would withstand any determined or prolonged assault.