Will the US follow Israel all the wy to hell and back?

If Israel attacks the Iranian Nuke site which need tactical nukes to destroy as they are build into a mountain near qhom, will the us retaliate if Iranian missiles start down on israel? The Iranian regime has been morphed into a vicious military dictatorship(from a brutal thocracey dictatorhip) which give Khamenie his orders now. The IRGC are a bunch of generals who believe the imam mahdi will only arrive though a moslim crusade or bloodshed.

These people are maniacs and if they get a nukes, they will blackmail he ntier internation community on a whim as they hold no popularity amongst their
own younger generation populace