According to the IAEA, Iran has around 400kg of 60% enriched Uranium. Nobody disputes this. There is zero reason to ever enrich beyond around 5% for civilian purposes, and zero reason to ever enrich beyond around 20% for non-bomb purposes (naval ship reactors typically use higher enrichment to avoid refueling and increase power density). That's enough Uranium to build around 10 bombs if fully enriched. They've done work on designing the actual bomb itself, too, and there's very little dispute about that either.

They have a nuclear weapons program. What Iran hasn't done, or there's no evidence of them having done, is actually start putting one together. But many of the prerequisites to do so are in place, though people dispute exactly how long it would take them to pull it off once they decided to do so.

Iran is considered a bellicose enemy in much of the middle east. A nuclear-armed Iran would quickly lead to the rest of the middle east pursing their own nuclear weapons programs to counter Iran.

A nuclear armed Iran leads to rapid nuclear proliferation throughout the middle east.

I remember an old interview of Robert Fisk where in which his analysis was that the only way to stay safe from attacks like this was to have a nuclear weapon.

I can't think of any other way. Their rhetoric is needlessly belligerent but it doesn't seem like there's anything they can do to guarantee their own safety.