After years of warning that an Iranian atomic bomb is right around the corner, Israeli officials now say Iran is at least four years away from deploying a nuclear weapon, maybe more. And Obama administration officials agree, although they shy away from endorsing a specific time frame. “We’ve gained some breathing space,” a senior U.S. official told me last week. “The good news is that we have slowed down the nuclear clock.”

U.S. and Israeli officials say their revised timeline is based mainly on reports that Iran is having trouble with its centrifuges, the machines that enrich ordinary uranium into the stuff used in weapons. Secretary of State Hillary Rodham Clinton gave credit last week to the economic sanctions the United States and its allies have imposed.

But the full story is more interesting than that. The Obama administration has applied a sophisticated array of pressures on Iran that go well beyond the sanctions and diplomatic “engagement” that have been the public face of its policy. The measures are showing results ― and for that, the administration deserves some credit.

One factor has been sabotage, including the implanting of a virus in the computers that control Iran’s centrifuges. Neither Israel nor the U.S. has claimed credit for that, but they haven’t criticized it either, and they readily acknowledge that it produced positive results.

Another key accomplishment has been a painstaking tightening of international export controls to prevent Tehran from buying the high-technology goods it needs to keep its program going.

“The sanctions, combined with new trade controls, have made it harder and harder for Iran to get key goods that they need,” said David Albright, a nuclear physicist and the author of “Peddling Peril,” a book on the illicit trade in nuclear components. He notes that as a result of the controls, the Iranians may be running out of maraging steel, a key material for making centrifuges.

And now that it turns out Iran is unlikely to produce nuclear weapons as quickly as was once feared, the Obama administration wants the world to know ― as part of its diplomatic strategy to slow Tehran down even more.

“The Iranians have a clear strategy to mislead everybody about how advanced their program is,” the U.S. official said. “We’ve stripped away that mask. This is not a massive program.”

That’s a message, he added, that the U.S. hopes will reach Iran’s leaders and its people, who are bearing the brunt of economic sanctions as the price of pursuing nuclear technology.

“If they think they are within grasp of a nuclear weapons capability, then their natural inclination will be to endure another couple of years of sanctions. But if they think they are still years away and are going to continue suffering economic damage, that makes it much more likely that they would decide, if only for tactical reasons, to accept some limitations on the program.”

U.S. officials say that the broad economic sanctions that the United States and other Western countries have applied against Iran are having an effect. They note decisions by international banks, insurance firms and oil and gas companies to reduce their business in Iran or pull out altogether.

But so far, those broad sanctions probably haven’t been as important as the narrower trade controls imposed by the U.S. and European countries against networks that smuggled maraging steel, carbon fiber and other materials useful for centrifuge technology to Iran.

The international trade controls still have at least one major weak spot: China.

“China does not enforce its trade controls or its sanctions adequately,” he said. “It’s a major problem.”

U.S. officials acknowledged that China’s uneven enforcement of technology exports to Iran is still a significant concern. The issue will probably come up in private during this week’s visit to Washington by China’s president, Hu Jintao.

Meanwhile, Albright and others warn that the revised estimates of Tehran’s capabilities are just that: estimates. There are several scenarios under which Iran could still manage to build a nuclear weapon before 2015, he said; it merely appears less likely now.

The Israelis have offered plenty of forecasts on Iran’s nuclear program that turned out to be wrong. In 1992, Israel’s foreign minister predicted that Iran would have a nuclear weapon by 1999; in 2001, the defense minister set the date at 2005; and just two years ago, Prime Minister Benjamin Netanyahu warned that the nuclear threshold would come by the beginning of 2011. In those cases, though, the Israelis were trying to get the world’s attention to a danger they feared no one else understood. Now, for the first time in memory, they are publicly putting more time on the clock, not less.

There’s still no guarantee that President Obama’s approach will work. If it does, it will still take long and painfully gradual work. But the first two years of diplomatic engagement and stepped-up pressure appear to have bought a precious commodity: time. That’s no small achievement.

By Doyle McManus, Los Angeles Times

Doyle McManus is a columnist for the Los Angeles Times. ― Ed.

(McClatchy-Tribune Information Services)