If Iran plans on doing anything large scale it’ll likely be (mostly) confined to unleashing their Hezbollah proxy to fire hundreds of missiles from So. Lebanon into Israeli cities. Not much we or Israel can do to defend against that except engage the Iron Dome ABMs. And Israel can retaliate without our direct military involvement — it’s all happened before. I don’t see this blowing up into a major Middle East ground war involving American troops.
Rumor has it that Israel has a EMP pulse weapon that will shut Iran down. I am not sure I believe it, but they could shut down Iran (including their nuclear capability) without casualties. I have heard it is being considered as a doomsday alternative.