The international atomic watchdog has been to some of the world's toughest locations, but nothing quite like Europe's largest nuclear power plant in an active war zone.
Nuclear inspections have been a key part of the Iran nuclear deal. Internationalinspectors stand to permanently lose access to key sites, unless the U.S. and Iran can find a way forward.
The International Atomic Energy Agency can have 130 to 150 inspectors to keep tabs on Iran's nuclear program. The U.S. is paying the largest share, but probably won't have inspectors inside Iran.