By Fareed Zakaria, CNN
I've been following the tense back and forth with Iran very closely. I continue to believe it is the single most dangerous crisis that we confront today. And I'm struck by the pessimism surrounding it.
Everyone seems to believe that whatever the momentary ups and downs, there is unlikely to be a deal between Iran and the great powers that will avert war and prevent Iran from acquiring nuclear weapons. But that's not clear. There is a path to a deal, if, as with any successful negotiation, both sides can come away with something.
What would a deal look like?
The United States has long demanded that Iran stop all enrichment of uranium, a process that allows it to produce the fuel necessary for an atomic bomb. Iran has insisted it has the right to enrich for a peaceful nuclear program. There is a way around the deadlock.
Washington has signaled that it will ask Iran to stop enriching uranium to 20 percent, the level from which fuel can be easily converted for military purposes. Iran has indicated that it might be willing to accept a limit and would enrich up to only 3.5 or 5 percent. Then Iran could claim that it has preserved its right to enrichment but it's very hard to weaponize from that level.
There are other sticking points but Iran almost accepted a deal in 2009 and proposed one in 2010. Statements from officials in both sides suggest they might embrace elements of those proposals.
The crucial point on which Iran must make deep concessions is comprehensive inspections. The 2011 International Atomic Energy Agency report lays out a series of indicators that Iran might be pursuing a weapons program. The great powers should use that as a checklist of activities that Iran would commit to refraining from and insist that Iran allow the IAEA unfettered access to its sites until the agency is satisfied that any military program has been shut down.
But Iran would have to receive some reward for accepting such unprecedented inspections, and the obvious option would be the relaxation of sanctions, step by step, as inspections proceed unimpeded.
Now, for any deal to stick, it has to be accepted by two groups. The first are the hardliners in Tehran, led by Supreme Leader Ayatollah Ali Khamenei. He might be amenable. Khamenei has consolidated power, and he might be secure enough to accept a deal.
He has beaten back the Green movement, accommodated one key rival, Ali Akbar Hashemi Rafsanjani, and sidelined another, President Mahmoud Ahmadinejad. Khamenei has also given himself room to make concessions on the nuclear program, saying recently Islam considers the possession of nuclear weapons a grave sin.
But if Iran does make concessions, the United States would have to be able to accept them and relax some sanctions. And this is where the second important group, Republicans in Washington, could be an obstacle. If they demagogue the deal, or refuse to reciprocate on sanctions, the whole thing will unravel.
The administration has handled its allies, Russia, China, the United Nations and even Tehran with skill. To succeed, however, it has to tackle its most formidable foe, with whom it has not had much negotiating success so far: Republicans.