A non-hysterical approach to the Iran nuclear issue is entirely possible. It should take several considerations into account. If the rattled and insecure Iranian leadership is lying when it says it has no intention of developing nuclear weapons, or if it undergoes a conversion from that position (triggered perhaps by an Israeli air strike), it will find, like all other nuclear-armed states, that the bombs are essentially useless and a considerable waste of time, effort, money and scientific talent.
Iran would most likely "use" any nuclear capacity in the same way all other nuclear states have: for prestige (or ego‑stoking) and to deter real or perceived threats. Historical experience strongly suggests that new nuclear countries, even ones that once seemed hugely threatening, like communist China in the 1960s, are content to use their weapons for such purposes.
Indeed, as strategist (and Nobel laureate) Thomas Schelling suggests, deterrence is about the only value the weapons might have for Iran. Such devices, he points out, "would be too precious to give away or to sell" and "too precious to waste killing people" when they could make other countries "hesitant to consider military action".
I have no love for the Iranian regime, but I have always considered the aggressive posturing toward Iran to have little to do with stopping them developing nuclear weapons. Even if they are and do get them (always a possibility), it will largely be a result of the aforementioned aggressive posturing by Israel and the West. An invasion of Iran is more of an economic and political move than a military necessity, as was Iraq I and II. No co-incidence that it is an election year in the US.