Iran and its six negotiating partners have returned to Geneva to try to conclude a deal to curb Tehran's nuclear program. Hopes are high after talks earlier this month seemed to nearly reach agreement, only to fall apart at the last minute. Now, participants are trying to keep expectations in line. While progress has been made, agreeing on final details will be difficult given Iran's red lines, Israel's opposition, and divisions in Washington.

The "P5+1" talks, which include Britain, China, France, Germany, Russia and the United States, have been going on for years, with little progress. Doubts continue to swirl around Iran's intentions, with Tehran insisting that its nuclear program is for peaceful purposes, while most other nations worry that it is attempting to acquire a capability that will allow it to build a nuclear bomb in a relatively short period of time. Secret facilities, incomplete and inconsistent reports to the international nuclear watchdog and steady progress in its capabilities prompted the United Nations to impose sanctions on Iran that have done great damage to its economy. The progress in the most recent negotiations is thought to have been driven by the toll those measures have taken.

In the last round of talks, a deal seemed imminent, yet agreement ultimately proved elusive when the P5+1 negotiators tightened terms at the last minute and Iran balked at the new conditions. The parties have returned to the table seeking an interim accord that would lay out confidence building steps that would in turn lead to a more substantive, long-term deal.