I am not concerned with a military retaliation from Iran. Israel already took out a lot of that capability, so while the bunker busters are falling, any offensive capabilities remaining should also be neutralized. This is not a difficult task — and I would expect that casualties would be kept to a minimum as well.
Iran has virtually zero war-making capability outside of missiles at this point, but it is also quite impossible to make war against Iran, given its immense size and treacherous terrain. The best approach is airstrikes to eliminate all naval, fighter and missile threats and leave it completely de-balled like Syria.