There are risks related to their proxies too, hamas, hezbollah, shia militias, whatever. Some of those clowns are looking for a clash big enough to change the mix in the entire mid-east. Iran will be working through them to do some damage to the U.S but the Iranians don't necessarily want their proxies to do something so barbaric that the Iranian homeland pays the price or so ugly that you can't put the genie back in the bottle. Unfortunately, a lot of the players don't have a fine-tuning knob on them- Trump included.
I do think that the Americans will accept a dance where there is cyber stuff and some grids taken down and general mayhem like that, and the bomb a refinery or two and so on. I mean you gotta give em a way out with their own people. But I don't know what the way out is if they think they are going to take a lot of American casualties, which certainly is probably their intent. Things will get worse right off with Trump in charge.
I know what would happen if the dems were in charge. The Russians would offer to broker a deal and they would show up in droves and set up more defense measures for the Iranians. Then the Russians would declare that an attack on Iran would be an attack on them if they are in the country. You know as when Obama got in trouble with Syria and red lines etc. Then Obama caved in by letting the Russians "broker a deal." ie. occupy and set up military bases and pretty much assure that Assad would not be overthrown.
And yes, Israel would do well to behave themselves, but Iran would also do well to not poke them right now too. So that is all for the good if both are smart enough to take advantage of it.