The P5+1 (the United States, United Kingdom, Germany, France, Russia, and China, facilitated by the European Union) has been engaged in serious and substantive negotiations with Iran with the goal of reaching a verifiable diplomatic resolution that would prevent Iran from obtaining a nuclear weapon, and on November 23, reached a set of initial understandings that halts the progress of Iran's nuclear program and rolls it back in key respects. A year ago Iran's nuclear program was growing and becoming more dangerous with each passing day. That is no longer the case. Iran has committed to halting certain levels of enrichment and neutralizing part of its stockpiles. Iran cannot use its next-generation centrifuges, which are used for enriching uranium. Iran cannot install or start up new centrifuges, and its production of centrifuges will be limited. Iran will halt work at its plutonium reactor. The Joint Plan of Action has temporarily blocked each of the paths Iran would need to go down to build a nuclear weapon. Many observers openly doubted whether Iran would keep its commitments under the Joint Plan. But according to the IAEA, Iran has done what it promised to do during these past 6 months.