To my mind the nuclear deal, Iran's nuclear programme and Trump's announcement are something of a red herring when it comes to what's going on in our region at the moment. The meaty issue is Iranian expansionism in the Middle East, through the basket case that is modern Iraq to the horrific chaos that is modern Syria and most specifically for Israel the placing of Iranian soldiers and bases right up against Israel's borders.
Add to this Hezballah's significant gains in Sunday's Lebanon elections and you have a rather worrying situation in view of the Iranian leaderships' very vocal calls for Israel to be wiped off the map.
Iran is keen on bases in Syria to increase their hegemony in the Levant, including by directly threatening Israel's borders. Almost every Israeli air strike in Syria and Lebanon over the last few years has been in order to prevent this Iranian plan from coming to fruition. Iran's actions in the region are absolutely a legitimate casus belli for Israel to mount preemptive strikes in self-defense. Israel cannot tolerate such a well armed and hostile force threatening its population centres.
I really don't think it's a matter of Bibi or Barak or whoever might be in charge, I don't see any Israeli prime minister acting differently in this case. I think Olmert was one of our worst PMs on record, but he did one thing right, the 2007 preemptive airstrike on Syria's nuclear installations.