It'll play out just like usual. One night a couple of dozen B52s will launch a bunch of cruise missiles from half way across the Mediterranian at about the same time that B2s drop their payloads over Iran. Communications, command structures, power plants, anti air facilities, and naval installations will be the primary targets.

Then a hundred more cruise missiles will be fired from ships and subs at about the same time that the B1s begin their high altitude super sonic runs across Iran, defended by all the electronic counter-measures the US can employ.

Finally, just before dawn the F22s will swarm in for precision strikes to reduce their anti air sites and to maintain air superiority to pave the way for several dozen squadrons of F18s and F15s which will reduce Irans military by half in about 72 hours. The UK will pitch in by firing a cruise missile from some lone destroyer and the French might send in a fighter plane. The Iranian navy and airforce will never participate in anything except their own decimation on the tarmac and in port.

I would expect some type of surprise from the US, as it is part of US military doctrine. I'm thinking an apparent ground invasion. US forces might faint with a small amphibious assault or airborne assault just to lure out Irans heavy ground forces so air assets can cluster bomb them into oblivion.

Within weeks starving soldiers will be surrendering to some F18 pilot that had to bail out over Iran for whatever reason.