If this deal is fully implemented, Iran will be unable to build a nuclear bomb by enriching uranium or by reprocessing plutonium for at least 10 years. Some of the restrictions imposed by this deal would last 15 years. The international inspections of certain aspects of Iran’s nuclear program would stay in place for 25 years.

As for the economic sanctions against Iran, they would be lifted not upon the deal’s signing, as the Iranians initially demanded, but only after the inspectors have verified that Iran has fulfilled all of its commitments in the deal.

These commitments include reducing the number of Iran’s installed centrifuges by two-thirds (from about 19,000 to 6,104, with only 5,060 allowed to enrich uranium); reducing its stockpile of enriched uranium by 97 percent (from 10,000 kilograms to 300 kilograms); to remove all advanced centrifuges (those that can enrich uranium at a much faster rate) and to place them in internationally monitored storage; to destroy the core of the Arak heavy-water reactor (which could produce a plutonium bomb), ship all its spent fuel out of the country, and forgo additional reprocessing; among other things.

...{I}it is a profoundly good deal; there has never been a nuclear deal, with any country, that is so comprehensively restrictive. Israeli Prime Minister Benjamin Netanyahu urged the U.S. Congress to demand “a better deal,” but his definition of such a deal-- one that bans uranium enrichment, dismantles all its facilities, and insists on a drastic change in Iran’s foreign policy-- is unattainable, and, more to the point, he knows it.

Yes, this deal wouldn’t keep Iran from being a menace in Middle East politics, or from repressing its own people. But no arms control deal can aspire to do that. The U.S.-Soviet strategic arms treaties, signed throughout the Cold War, didn’t require the Soviet Union to disavow communism, end its support of Third World insurgencies, or institute Jeffersonian democracy-- but the deals were still very useful. They capped, and in the later years reversed, the nuclear arms race; and they provided a forum for diplomacy, a cooling-off of the distrust and hatred, at a time when no other issues could have done so.

“Nothing in the deal described by the administration this afternoon would justify lifting U.S. and international sanctions,” said former Florida Gov. Jeb Bush, one of the leading contenders for the Republican presidential nomination. “I cannot stand behind such a flawed agreement.”

Florida Sen. Marco Rubio, one of the fiercest critics of the deal and also expected to announce a White House bid, vowed to work with his colleagues on Capitol Hill to review the deal and perhaps seek additional sanctions to ensure Iran doesn’t obtain a nuclear weapon. Mr. Rubio is one of four Senate Republicans considering a White House run who signed a letter last month warning Iranian leaders that Congress might try to unravel the deal.

“The initial details appear to be very troubling,” Mr. Rubio said after the deal was announced. “Tehran is gaining international acceptance of its nuclear ambitions and will receive significant sanctions relief without making serious concessions.”

Mr. Walker went a step further when he told a Wisconsin radio host on Thursday that one of his first acts as president would be to dismantle the deal.