It is very likely false that Iran had nuclear weapons, or was within weeks of having them. This was also the position of US intelligence, until they were forced by higher-ups to speak different words.

Of course, Iran very much wanted the ability to make a nuke, and they probably could have had one ready in 1 or 2 years. But the proof put forward in defense of this strike is claiming Iran was weeks away from nukes. That proof is dubious.

(Also interesting to consider how US retreat from the nuclear deal under Trump 1 has affected and shaped the current situation)