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Iranian women chant slogans during an anti-US demonstration outside the former US embassy headquarters in the capital Tehran on May 9, 2018. - Iranians reacted with a mix of sadness, resignation and defiance on May 9 to US President Donald Trump's withdrawal from the nuclear deal, with sharp divisions among officials on how best to respond.
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Story highlights

Iran, the U.S. and others agree on a historic nuclear deal in Vienna

It sets the stage for lifting sanctions on Iran, comprehensive inspections

Obama: "If Iran violates the deal, all of these sanctions will snap back into place"

(CNN) —  

The devil is in the details.

That adage is particularly true for a deal as contentious and complicated as the one reached Tuesday over Iran’s nuclear program.

Iran and its longtime adversaries, including the United States, have been working at it for years. In a relationship long rife with mistrust, checks and counterchecks are a must for any agreement. It’s a logistical challenge to figure out how to inspect sensitive, highly secured sites around a large country. And this is nuclear science we’re talking about, after all, hardly a topic to breeze through casually.

Here are some highlights from the historic agreement announced in Vienna, Austria, as related by the U.S. government and Iranian state media.

Deal aims to limit nuclear threat, open trade

Iran will have a nuclear program, to a point

Does this deal eliminate Iran’s nuclear program? Or does it let it continue unimpeded?

No and no. The truth lies somewhere in the middle.

The Joint Comprehensive Plan of Action, as this deal is being called, states point blank that “Iran reaffirms that under no circumstances will (it) ever seek, develop or acquire nuclear weapons.” The distinction is between nuclear weaponry and nuclear power.

Iran’s state-run Islamic Republic News Agency stresses that, under the deal, “world powers have recognized Iran’s peaceful nuclear program and are to respect the nuclear rights of (Iran) within international conventions.” By this, it means a country’s right – including Iran’s, since it signed the Treaty on the Non-Proliferation of Nuclear Weapons – to enrich nuclear fuel for civilian purposes.

The IRNA report stresses no Iranian nuclear facilities or centrifuges will be dismantled, including the Arak heavy water reactor. It also states “the policy of preventing enrichment uranium is now failed and Iran will go ahead with its enrichment program.” And Iranian students now can be allowed to study in nuclear fields.

But none of this means Iran’s nuclear program won’t change significantly.

World reacts to landmark deal

What Iran must do on nuclear matters

Iran’s government didn’t focus on what its government must do to diminish its nuclear program, but the U.S. State Department did, in its synopsis of the agreement. It says that Iran will:

• Keep its uranium enrichment levels at no more than 3.67%, down from near 20%.

• Maintain a uranium stockpile (at the above prescribed level) under 300 kilograms, well below its current 10,000-kilogram stockpile. President Barack Obama says this works out to Iran reducing its nuclear stockpile by 98%.

• Phase out its IR-1 centrifuges within 10 years, keeping over 5,000 centrifuges running during this stretch at its Natanz facility. “Excess centrifuges and enrichment-related infrastructure at Natanz will be stored under IAEA continuous monitoring.” (The IAEA is the International Atomic Energey Agency, the U.N.’s nuclear watchdog.) Nationwide, Obama said that Iran will put away about two-thirds of its roughly 19,000 current centrifuges.

• Not have any nuclear material at its Fordow facility for 15 years, converting that site “into a nuclear, physics and technology center.”

• Limit certain research and development activities for the next eight years.

• “Design and rebuild a modernized heavy water research reactor in Arak … using fuel enrichment up to 3.67%” after getting international authorities’ OK on the final design. “The reactor will support peaceful nuclear research and radioisotope production for medical and instructional purposes.” Iran will not add any other heavy water reactors for the next 15 years.

• Ship spent fuel outside its borders.