It was a good deal that constrained enrichment, allowed human inspectors to roam and legitimately raise complaint if kept from chasing leads, permitted installation of tamper resistant / tamper revealing fixed monitoring instruments.

It addressed neither missiles, late library fees, digital piracy, etc.

It was flawed in the same sense a car is flawed for not being able to pull a 820 Flexi-Coil 18 metre bar, with a 2320 tow behind Flexi-Coil airseeder across a muddy field.

( eg: outside of design scope )

Worth noting also - not just a US deal - a number of other countries had input on the deal and on inspections.