Iran will NEVER be allowed to have nuclear weapons as they are a proven international sponsorship of global terrorism and are an irresponsible state (calling for the wanton destruction of another state is only one example). Just like Syria last year, Iraq back in 1981, North Korea, if we or any other reputable intelligence agency has verifiable evidence of a nuclear weapon production site, it WILL be taken out, period.
And yes, the international community has every right to tell a non-compliant state how to behave and impose sanctions if it doesn't, or, in the extreme, take military action to remove the leadership.
Ha! proven aggressive states have nukes and are certainly allowed to exist as nuclear powers.
Just 'taking out' a site in someone else's country also sends a clear message
- ignore international law, might makes right, and he who has the biggest gun makes the rules.
That is not a recipe for 'compliance' or peace. Of course if those are not the goals, then all is well.