secretary kerry, foreign minister zarif, federica mogherini, foreign minister lavrov of russia, all these people spent hours and hours and hours together. this was a very complex, intense process. before the deal, the world had relatively little visibility into iran's nuclear program. today international inspectors are on the ground, and iran is being subjected to the most comprehensive, intrusive inspection regime ever negotiated to monitor a nuclear program. inspectors will monitor iran's key nuclear facilities 24 hours a day, 365 days a year. in all countries that the agency goes, material is measured... material is put under seal. we use agency... double cap metal seals with an i.d. number on it that inside has striations that are unique to each seal. marek: surveillance cameras are installed to maintain some knowledge about what is going on in that facility. we try to do our job in a relatively straightforward, scientific-based manner and so...'s easy to und. kimball: well, it's been two years since the conclusion of the iran nuclear agreement, and it has been a very good success. th