Joby Warrick and Glenn Kessler report in The Washington Post that Iran is experiencing setbacks in its uranium enrichment efforts.Excerpt follows from Technical setbacks cause Iran to falter in push to enrich uranium, report says:

Iran is experiencing surprising setbacks in its efforts to enrich uranium, according to new assessments that suggest that equipment failures and other difficulties could undermine that nation’s plans for dramatically scaling up its nuclear program.

Former U.S. officials and independent nuclear experts say continued technical problems could also delay — though probably not halt — Iran’s march toward achieving nuclear-weapons capability, giving the United States and its allies more time to press for a diplomatic solution. In recent months, Israeli officials have been less vocal in their demands that Western nations curtail Iran’s nuclear program.

Indications of Iran’s diminished capacity to enrich uranium arise just as the Obama administration begins to take sterner action to compel Iran to abandon enrichment. On Wednesday, the Treasury Department announced new U.S. sanctions against companies it says are affiliated with Iran’s Revolutionary Guard Corps, a key player in the country’s nuclear and missile programs.

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Beneath this rhetoric, U.N. reports over the last year have shown a drop in production at Iran’s main uranium enrichment plant, near the city of Natanz. Now a new assessment, based on three years of internal data from U.N. nuclear inspections, suggests that Iran’s mechanical woes are deeper than previously known. At least through the end of 2009, the Natanz plant appears to have performed so poorly that sabotage cannot be ruled out as an explanation, according to a draft study by David Albright, president of the Institute for Science and International Security (ISIS). A copy of the report was provided to The Washington Post.

The ISIS study showed that more than half of the Natanz plant’s 8,700 uranium-enriching machines, called centrifuges, were idle at the end of last year and that the number of working machines had steadily dropped — from 5,000 in May to just over 3,900 in November. Moreover, output from the nominally functioning machines was about half of what was expected, said the report, drawing from data gathered by the International Atomic Energy Agency, the U.N. nuclear watchdog.

A separate, forthcoming analysis by the Federation of American Scientists also describes Iran’s flagging performance and suggests that continued failures may increase Iran’s appetite for a deal with the West. Ivan Oelrich, vice president of the federation’s Strategic Security Program, said Iranian leaders appear to have raced into large-scale uranium production for political reasons.

“They are really struggling to reproduce what is literally half-century-old European technology and doing a really bad job of it,” Oelrich said.

The findings are in line with assessments by numerous former U.S. and European officials and weapons analysts who say that Iran’s centrifuges appear to be breaking down at a faster rate than expected, even after factoring in the notoriously unreliable, 1970s-vintage model the Iranians are using. According to several of the officials, the problems have prompted new thinking about the urgency of the Iranian nuclear threat, although the country has demonstrated a growing technical prowess, such as its expanding missile program.

“Whether Iran has deliberately slowed down or been forced to, either way that stretches out the time,” said Patrick Clawson, deputy director for research at the Washington Institute for Near East Policy, a nonpartisan think tank.

But analysts also warned that Iran remains capable of making enough enriched uranium for a small arsenal of nuclear weapons, if it decides to do so. Iran has announced plans to build 10 new uranium plants, and on Monday the government said it would begin increasing the enrichment level of some of its uranium, from a current maximum of 3.5 percent to 20 percent. Enrichment of 90 percent is considered weapons-grade.