It would be good if it stopped there. I am not sure that it would. Iran has undoubtedly learned the lesson of Iraq and has decentralized their nuke program. I doubt a single airstrike, or a small number of airstrikes, will put a serious dent in Iran's program.
It's entirely possible we'll see a nuclear exchange between Israel and Iran. This would be very, very bad, regardless of any other consideration.
And the result will be as many as 35 million dead in under 30 minutes.