If Israel strikes Iran, the whole Arab world will do nothing because they know Israel has enough nukes to take out every single Arab/Muslim capital several times over if they try to attack. And if the offending nations are decapitated, the state-sponsored terror groups will shrivel and die due to lack of sustenance.Though, I certainly wish that was true,(and it might be) but I have a hard time believing it.
I think Israel would rather dissolve than nuke every major Arab capital based on the threat of being nuked.