The U.S.-led deal to freeze Iran’s nuclear program is a great accomplishment on many levels. Begin with the most basic: What if the talks in Geneva had failed?

If Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif had gone home empty-handed, we would likely be drifting toward war. Iran’s uranium-enrichment centrifuges would continue whirling until it became unambiguously clear that the nation, if it chose, could make a “breakout” dash to build a nuclear weapon in a matter of weeks — something President Obama has said he will not allow.

The president could decide to attack Iran’s nuclear facilities or he could wait until Israeli military action forced his hand. Either way, we’d be engaged in another Middle East war — one whose economic, political and human consequences could be dire.

So what did Kerry do in Geneva? He won an agreement that not only freezes Iran’s nuclear-enrichment program for six months but actually rolls it back; that prevents new nuclear facilities from coming online; and that provides for unprecedented daily inspections to ensure that Iran is living up to it commitments.

Let me restate that to make it clearer: In May of next year, Iran will be further away from being able to build a bomb than it is today.

And this achievement is being attacked with the word “appeasement” and references to Munich? Give me a break.

In return, the United States and other leading nations have agreed to suspend some minor sanctions that mean a paltry $7 billion to the Iranian economy. Even if negotiations for a permanent agreement ultimately fail, this is a bargain price for six months of peace — six months, mind you, during which the Iranian nuclear program goes backward, not forward.

Critics complain that the agreement recognizes Iran’s right to enrich uranium, if only in low concentrations that are useless for bomb-making. In fact, the Geneva accord is deliberately ambiguous on this issue. But it should be clear by now that sanctions, however draconian, will never halt Iran’s enrichment program. In 2006, when the first U.N. sanctions were applied, Iran had at most 3,000 functioning centrifuges that produced enriched uranium at a concentration of just 3.5 percent. Now Iran has at least 18,000 centrifuges and is able to enrich uranium to the level of 20 percent — which is nine-tenths of the way toward making fuel for a bomb.

Under the Geneva pact, half of Iran’s 20 percent uranium will be diluted and no more will be produced. A military strike that eliminated half of the potential fuel for a “breakout” bomb — and wiped out the capability to make more — would surely be reckoned a success. It is just plain dumb to attack Kerry and Obama for achieving the same thing without firing a shot.

Critics can’t plausibly oppose the agreement on practical grounds. The real reason they are freaking out is that the agreement was made possible by the most extensive high-level bilateral contacts between Washington and Tehran since the 1979 Iranian revolution. This has the potential to reshape the whole region — to the detriment of those vested in the status quo.

With vast reserves of oil and a population of 80 million, Iran has the dimensions, and the ambitions, of a regional superpower. The election of President Hassan Rouhani — a “moderate” in the context of the radical Islamic regime — suggests Iran may be ready to change its relationship with the West from confrontation to coexistence. Obama has signaled a willingness to test this proposition.

Just as Richard Nixon’s opening to China unsettled U.S. allies in Asia, so has Obama’s phone call with Rouhani unnerved our allies in the Middle East. Israeli Prime Minister Benjamin Netanyahu, who should be cautiously pleased that the threat from Iran is at least temporarily diminished, has reacted with irrational outrage. Saudi Arabia’s autocratic leaders are sulking and grumbling.

It may be that Iran is incapable of becoming a responsible actor on the world stage as long as it is led by the mullahs. But there was a time when it was hard to imagine China being anything but a pariah as long as it was led by the Maoists — yet now, Beijing is the capital of one of the world’s economic superpowers, with Mao’s picture still watching over Tiananmen Square.

Regimes do evolve, sometimes in ways that make the world a safer place. Obama is boldly asking this question: Can it happen in Iran?

Eugene Robinson’s e-mail address is eugenerobinson(at)

© 2013, Washington Post Writers Group

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