The final agreement lies somewhere in between the April 2 interim parameters and Khamenei's maximalist demands, but whether Iran will adhere to the seemingly favorable terms is another question.
The P5+1 agreement with Iran just announced is not a "good" agreement. Its problems start with the administration claiming that it blocks the path to nuclear weapons. In fact, this agreement, unlike outcomes with the Libyan, Iraqi, and Syrian (and, temporarily, North Korean) nuclear programs, does not eliminate the ability of the target state to produce sufficient fissile material for nuclear weapons.
Rather, it gives Iran incentives not to undertake such an effort, as well as time for the international community to spot and react to a nuclear weapons breakout effort by imposing new sanctions or a military strike. And that makes it by definition a "bad" agreement.
Apart from the Iranian agreement to replace the core of the Arak heavy water plant (which does cut off the road to fissile plutonium), the Iranians will still have the capability to rapidly develop enough fissile material for one or more nuclear devices. What this agreement does is extend the time to amass such material from the current two to three months to approximately a year.
This is done by Iran agreeing for periods of 10 to 15 years to limits on the number and type of centrifuges it can operate (5,000 plus of their most basic model doing enrichment out of the 19,000 they have), the amount (300 kilograms) and level of enrichment (3.6 percent; 90+ percent is needed for fissile material), and the sort of research it can do on advanced enrichment technology. These physical restraints are coupled with far more stringent international inspection and monitoring by the International Atomic Energy Agency (IAEA) to ensure Iran adheres to the agreement, and does not cheat or operate secret installations as it has done in the past.
This "time line," along with high confidence that any Iranian effort to break out of the agreement's restraints would soon be spotted by the IAEA, serves to restrain Iran by giving the international community time to re-impose sanctions or other diplomatic and economic measures to push it back to compliance, or in extremis to use military force against installations enriching uranium. In return, the international community will remove all the Iran sanctions at least related to its violations of the Nonproliferation Treaty and UN Security Council resolutions. This will allow Iran to recover well over $100 billion in oil earnings frozen in foreign bank accounts, and to begin exporting oil freely, which would lead rapidly to a doubling of its exports to 2+ million barrels a day. This would greatly expand Iran's financial and economic power. It would also give Iran a relatively positive "bill of clean health" on its nuclear program.
But what is at play between the Iranians, the P5+1 (the US, China, Russia, Britain, France, and Germany, with the EU as organizer) and the US Congress goes far beyond centrifuge capabilities and inspection protocols. Under the "Iran Nuclear Agreement Review Act," Congress has 30 days to review the agreement, or 60 if submitted when Congress is in recess. Thus while this process goes on, there can be no implementation of the agreement.
The Obama administration saw this agreement as "transformational," the harbinger of a new relationship with Iran, "flipping" it to become not a threat to regional security but a supporter of it, and a possible partner of the administration. Vice President Joe Biden, however, saw the impending deal as "transactional," i.e., similar to nuclear arms agreements with the Soviet Union which resolved specific potentially destabilizing situations without removing the underlying conflict between the West and the Soviet bloc.
Some Iranians, like President Hassan Rouhani and Foreign Minister Mohammad Zarif, wanted a transactional agreement that would allow Iran to maintain its nuclear infrastructure and potential for nuclear weapons while ending sanctions. Supreme Leader Ali Khamenei, however, clearly wanted an agreement that would "exonerate" Iran, erase any sign of culpability for its violations of the Non-Proliferation Treaty, and allow him to argue, in his quest for dominance of the entire region, that the US and the UN Security Council had yielded and now admitted Iran was in the right in its nuclear policies.
To the extent the Obama administration yielded on his demands that surfaced after the April 2 interim accord on the principles for a final agreement, Khamenei could claim the US wanted the deal more than the Iranians did. Clearly the administration was not willing to accept all of the demands raised after April 2. The agreement finally reached represents a compromise between the April 2 accord and the maximalist demands of Khamenei. Whether Iran will adhere to what from any viewpoint is a good deal for it is another question.
In the end, the only guarantee that Iran will not, like North Korea, develop nuclear weapons is the threat of military force. The administration has emphasized readiness to strike Iran if on the verge of a nuclear weapons capability, but whether the US would make good on this pledge is also another question.
James Jeffrey is the Philip Solondz Distinguished Fellow at The Washington Institute.