The heavy water facility at Arak will be inspected under terms of the nuclear deal being negotiated between Iran and the P5+1 countries. Arak, Iran, January 15, 2011. (Hamid Foroutan/AFP/Getty Images)

The heavy water facility at Arak will be inspected under terms of the nuclear deal being negotiated between Iran and the P5+1 countries. Arak, Iran, January 15, 2011. (Hamid Foroutan/AFP/Getty Images)

The French ambassador to the Iran nuclear negotiations said this week that it was unlikely a deal would be struck by the June 30 deadline. There are still considerable details to work out, particularly over procedures for verifying Iran’s future nuclear activities, and the lifting of economic sanctions in return for Iran’s compliance with the requirements of the so-called P5+1 negotiating countries.

Nonetheless, the Iran agreement remains on course to become one of the most significant nuclear non-proliferation achievements in history. If fully implemented in line with the draft framework announced in early April, it will block Iran’s path to nuclear weapons capability.

The agreement reduces Iran’s capacity to enrich uranium, closes the plutonium pathway to the bomb, and greatly increases international monitoring and verification. What follows is an analysis of the key details still being hammered out at the negotiating table. Read more