Good, most US generals agree this is the best way to keep Iran from building an atomic weapon and the only real alternative is war where we send in 250,000 troops and outright invade this country. Losing probably 10-15,000 men. Iran's military is far stronger than Iraq's was.
And to be clear, they aren't developing a 'nuclear' weapon. They COULD soon have capability to build an atomic weapon.
The difference is huge. An atomic weapon would have a yield somewhere from .1 kilotons to 15 kilotons. An average nuclear device, a thermo-nuclear bomb, has a yield of 3,500 kilotons. The largest t-nb the US detonated was 25,000 kilotons. The largest ever, the Tsar bomb detonated by Russia, had a yield of 50,000 kilotons.
Its easy to scare people when you say "Iran will have a nuclear bomb soon". No, they won't.
And with this treaty they likely will never have an atomic weapon let alone a nuclear weapon.