Use small nukes, airbursts mostly. Nuclear winter will not be a problem. NW scenarios require ground bursts to throw up lots of dust, and/or long lasting fires to put up lots of smoke. Stay away from the oil (or use enhanced radiation devices in those areas) and there isn't that much to burn in much of the Islamic world, especially the more troublesome parts from Gibraltar to the Indian subcontinent. Stone or concrete buildings and mud huts don't burn much, and they have no forests, nor even major grass or croplands, near the targets of interest.
So how many million men women children do you figure we'd have to kill?