First of all, the “billions” that opponents of the Iranian Agreement often cite was not American money; it was the Iranian people’s own money that has been held since the hostage crisis.
Secondly, nuclear technology is a product of cultural diffusion, it can’t be permanently stopped, but what the violated agreement had done was buy both countries time to detente.
Thirdly, no one in the US wakes up worried about UK or French nukes, or really even Chinese or Russian nukes, because we have relationships. The abridged agreement had given both parties time to build a relationship that would make the weaponization of nuclear technology meaningless.
And now it’s on life support, but not gone yet, because someone’s ego was hurt in the 2011 Washington Correspondents Dinner. The master of the Art of the Deal will hopefully repackage the agreement with his name on it after getting his ego soothed by ridding the agreement of Obama’s name, and then we can continue the path of building sustainable peace.
I am also unaware of how/why the same voices denouncing the Iran Agreement are congratulating the apparent diplomatic movement with North Korea. At this point, we have words, not action. Engaging with a rival is either a good strategy or it isn’t. Either Obama and Trump are to be encouraged for engaging Iran and NoKo, or both Administrations ought to be ridiculed. To choose one engagement over another is myopic partisanship.