The ONLY reason that Iran has a nuclear program is to provide it the means to make a nuclear weapon. To say that a country swimming in oil and gas needs nuclear power for energy generation is risible. They have long term form in hiding nuclear production facilities and enriching uranium way past any possible peaceful use. As soon as Iran makes a bomb the security calculus in the area immediately and permanently changes. The options to constrain the malevolent reach of Iran's fanatical leadership is dramatically reduced. The senior leadership of Iran routinely call for "death to America and death to Israel" so I would suggest that eliminating Iran's nuclear weapons is in the national security interests of the US.
I firmly believe the right thing to do is to bomb every nuclear or nuclear related site to dust, but then follow up with a relaxation of sanctions contingent on Iran not rebuilding any of its infrastructure. This is a Middle East inflection point. The combination of the destruction of Iran's proxies along with the collapsing Iranian economy gives the US and Israel an unprecedented chance to reorder the security situation in the area. Time for the US to step up.