And I think you well may be correct in your assessment. If your(not yours personally, but the adversary) whole desire is to create chaos, mass casualty, etc. then swoop into control in the aftermath, your proposed scenario works well. If radical islamists want to bring Egypt and others to their knees, starve or kill off 2/3 or more of the population and rule the remnant, then yes that is a strategy.
If you want to take over and retain the bulk of the wealth and infrastructure, maybe not so much.
In any anihilistic approach, there is no room for error. Failure to completely eradicate your opponents sows the seed of your own destruction. Push come to shove, Israel can drop a half-dozen retaliatory nukes and surround themselves in a sea of glass.
Faced with their own extinction, they are prepared to do this. The US is not so determined, I suspect, so the ugly face-to-face, field-by-field scenario may well play out here.
The day Israel uses nukes is the day Israel is lost. This is not 1945 with one nuclear power or a vast ocean between the bomb dropper and fall-out.
Remember, the Islamists want to effectively go back to the period around 800 to 1,000 AD or so.
Living in mud huts seems to appeal to them.
Israel better start developing their own gas sources, Real Quick.