Israel does not say they don't have nuclear weapons. They refuse to confirm or deny suspicions(knowledge) that they do.
Also, the "weeks away" thing is true, or a slight exaggeration at most. The targeted distance of the nuclear deal was to keep them 12 months away from producing nuclear weapons. Nuclear weapons are not as difficult to make as they used to be, it doesn't take years of collaboration between some of the greatest scientists in the world any more, the science is known. The only major barrier is Uranium enrichment.
Under JCPOA Iran was not allowed to enrich uranium past 3.67%, which is suitable for generating nuclear power. As I said, the aim of JCPOA was to keep them one year from acquiring nuclear weapons, which is how long it would take if they only had 3.67% enriched uranium.
Uranium enriched to 84% was found in Iran a few years ago, they claimed this was an unintended fluctuation. Fine, that's possible although not altogether likely, but let's take it at face value... It was not an unintended fluctuation from 3.67%, this would not be at all possible. It's possible it was an unintended fluctuation from 60%. They've been openly enriching uranium to 60%, which is one step under weapons grade. They have enough 60% uranium to make 10 nuclear weapons if it is enriched to 90%. America, Russia and several other nuclear powers could do this in a couple days. How long it would take Iran is somewhat speculative but 2 months is about as high as realistic estimations get. 2-3 weeks is entirely possible.
while this is all true, and im against iran having 60% enriched Uranium, there's something missing. why would a country want 60%? is it only to then enrich to 90%? is there zero other purpose?
of course not, its below weapons grade, but can be enriched to weapons grade quickly, in case of an invasion. having those nuclear sites was the only thing stopping Israel from attacking them for a few decades now. then we bombed the sites into a broken state. they could rebuilt but it may take a year or more. and what happened in that year? well, israel shifted instantly from "they are making a bomb, they're weeks away" to "they have too many ballistic missiles, they're going to attack us with them".
why does this matter? because from the start israel's narrative has been "iran wants a bomb to use on israel", when in reality its actually "iran wants sub-weapons grade uranium to prevent an attack from israel and the united states". they lose the uranium, they got attacked, their leader is dead, they can only really launch missiles and wait for an invasion.
and to top it off israel told us they were going to attack, knowing that our bases would be shot at in return, leaving us no choice but to strike first. to preemp a reactionary strike by iran.