5 Reasons Why An Iran Nuclear Deal Is So Elusive

— -- Secretary Kerry joined his European Union and Iranian counterparts in Vienna Wednesday for talks on Iran’s nuclear program, with just over a month to go before the negotiations expire.

Kerry demurred Tuesday when he was asked whether the parties involved in the talks would be willing to extend them past the Nov. 24 deadline, saying a deal before then wasn’t totally out of reach, but “we have some tough issues to resolve.”

Iranian Foreign Minister Mohamed Zarif and U.S. top negotiator Wendy Sherman continued talking, but a senior State Department official told reporters in Vienna Wednesday night that main issue was "sort of everything."

The core challenge behind most of the individual issues is what the P5+1 (the five permanent members of the U.N. Security Council plus Germany) think Iran needs for its stated goal of a strictly peaceful and research-driven nuclear program. Iran’s leaders continue to insist that they have an inherent right to enrichment and that restrictions curtail that fundamental right.

But here’s some of the specific issues that the international community and Iran have not been able to agree on yet.

1. How much power does Iran need for a peaceful nuclear program? The Iranians currently have about 10,000 “first-generation” (the least powerful kind) of centrifuges used to enrich uranium. The lower the generation, the longer it takes to enrich an amount of uranium needed to make a bomb (known as “breakout capacity”). The P5+1 want Iran to cut its total, permanent number of centrifuges in half, asserting that if Iran’s nuclear program is truly peaceful, it doesn’t need that many centrifuges.

2. And how do we measure Iran’s power? Iran is now developing more sophisticated “generations” of centrifuges which will be able to enrich uranium more efficiently – meaning it would take fewer centrifuges to make uranium weapons-grade. The way to work around that is for a final deal on centrifuges to be measured by the total power of the centrifuges (represented in “separative work units, SWU’s”) rather than the actual number of centrifuges it has. That’s super in-the-weeds, but hasn’t been agreed upon yet.

3. Why do they need Arak? The unfinished Arak heavy-water reactor in Iran is a major sticking point. Its design means it’s well suited to produce plutonium, which can also be turned into bombs. The P5+1 wants to get rid of Arak altogether, but Iran has proposed to change the design of Arak so that it produces less plutonium. Less plutonium means less breakout capacity for a bomb.

4. No secrets: The P5+1 is also concerned about Iran’s “sneak-out” capabilities, meaning its ability to build an enrichment plant in secret to covertly make bomb material. To combat this, they want the International Atomic Energy Agency to have broader authority to conduct surveillance within Iran, and their ability to inspect, with no notice, all facilities both declared to the international community and whatever secret facilities the IAEA comes across.

5. Sanctions: Iran and the P5+1 need to agree on a way to phase out current international sanctions as part of a final agreement. That is extremely complicated and depends on passage of a U.N. Security Council Resolution on Iran’s nuclear program and political involvement by the EU and U.S. Congress to revise legislation that unwind the sanctions, per the Arms Control Association.