The US simply will not nuke another country. Look at how the world always points their finger at us for bombing Japan. It simply is not going to happen. IMO, this is just America moving its chess pieces to put pressure on Iran. The question will be if Iran calls America on its bluff. I say, with 80% certainty, they will call America on its bluff. They know America just doesn’t have the resources, money or manpower, to fight three wars at once. Iran has the ability to rampantly step up the insurgent attacks in Iraq. So it’s a very bold but risky move by the US government. I would say there will be some small tactical strikes by stealth bombers at suspected military sites, but that would be about it.
It apperas they want to use "mini-nukes" that explode underground. If you have ever been to the middle east, you would know that this is a bad idea and is not safe for civilians. Most of the construction is not made to withstand earthquakes. Look what happened not to long ago. This will backfire and kill many unintended civilians because of the shock waves created underground, destroying peoples homes.