Kerry defends Iran nuclear deal to lawmakers

Aired: 7/23/2015 | 0:05:02 | Clip
There were testy exchanges and blunt talk in a Senate hearing on the Iran nuclear agreement. Republicans criticized the deal, and suggested that even if it passes Congress, it could be rolled back by the next administration. Secretary of State John Kerry fought back, saying that the consequences of rejection would be a "big green light" for Iran to increase uranium enrichment. Gwen Ifill reports.