No one knows, because its never been tried. I suspect nuclear weapons are incapable of "wiping out" Iranian capability. That doesn't mean someone might not try it, if there are no other options. It could be degraded, but to "truly wipe it out", given how military sites, forces, people, know how, is dispersed, you would need to destroy every single city. At the end of WW2, Germany was in literal ruins. Every single city was a ruin. The German Armed forces were still 9 million strong, only 2 million of those were old men and boys. They still had upto 9000 armoured vehicles and 5000 aircraft; on paper, considerable. In reality, short of fuel and ammunition. The challenge in Iran is that, of their forces, the Americans have only encountered missiles and drones. The drones are easily made in small workshops. To make them into weapons, they need explosives of some kind integrated, but with FPVs you don't even need that, if crashing one of these things into someone is enough. Are the Iranians making missiles? If they are, its in buried bunkers. But obviously they have a considerable secreted stockpile. If you knew where those stockpiles were, you don't need nuclear weapons. Nuclear weapons could be used to destroy the transport infrastructure; railheads, bridges, riverine docks. This is more lunatic talk. It would be immoral. The US military would not carry out an illegal order, but they would suggest to the President an order that is "legal".
