Barack Obama and other leaders of a declining West knew they couldn't do diddly squat about Iran's nuclear weapons program but were lured by Iranian money. So they made virtue out of necessity with the JCPOA and got retroactive approval from the UN Security Council.
Bully Donald Trump blows up the accord because he said he would do so, using the fuse Obama provided him by tricking Congress and RINOs.
Trump and a declining West still can't figure out what to do next. For now, Trump is happy, the Europeans are mad and the ayatollahs are chuckling. Sounds about right, does it?