in what universe is that happening? you think the world is safer with even a 10% likliehood of the world's largest terror network getting access to WMD? you're off your rocker.
The US over the past few decades and Russia over the past five years and Israel over the past year have inflicted quite a bit of terror, and they all have nuclear weapons.
None of them would have done it if their victims had them.
Iran's contribution to inflicting misery, death, and indiscriminate destruction on the world is a rounding error in comparison, and its bound by the same formula of MAD as anyone else is.