It wouldn't seem to be in the iranian government's interest to arm a terrorist group with a nuclear weapon - it would, however, be in their interest to arm themselves with a nuclear weapon.
Given the anti-iranian rhetoric coming, particularly, from the USA, if I was an Iranian, I would most certainly want a nuclear weapon, if only to protect myself.
Given the anti-iranian rhetoric coming, particularly, from the USA, if I was an Iranian, I would most certainly want a nuclear weapon, if only to protect myself.