Israel needs to declare they will nuke all areas providing and launching missles, tell the people to leave, and create a larger israel with a hefty kill zone for what they know is coming.
And on the Iran side, look for the Iranians to start a massive civil defense build up, of shelters and stock piling of essentials to tip us off that an Iranian first strike is eminent. The Iranians will have amassed a secret stock pile of at least one hundred atomic weapons and the civil defense build up will be the only warning that something is in the works.