an and the West have been at odds over its nuclear program for years. But the dispute has picked up steam since November 2011, with new findings by international inspectors, tougher sanctions by the United States and Europe against Iran’s oil exports, threats by Iran to shut the Strait of Hormuz and threats from Israel signaling increasing readiness to attack Iran’s nuclear facilities.
In late August 2012, international nuclear inspectors reported that Iran had already installed three-quarters of the nuclear centrifuges it needs to complete a deep-underground site for the production of nuclear fuel.
The report by the International Atomic Energy Agency detailed how Iran used the summer to double the number of centrifuges installed deep under a mountain near the holy city of Qum, while cleansing another site where the agency has said it suspects that the country has conducted explosive experiments that could be “relevant” to the production of a nuclear weapon.
The report was followed by new efforts by Prime Minister Benjamin Netanyahu of Israel to step up pressure on the Obama administration to establish “red lines” of intolerance for Iran’s nuclear activities. In September, during a speech at the United Nations, Mr. Netanyahu warned that Iran’s capability to enrich uranium must be stopped before the spring or early summer of 2013. The speech suggested that Israel would not take military action on its own before then.
Israel has been pushing the United States to take military action to damage Iran’s program before it reaches the point at which it has the capability to make an atomic bomb, or to give Israel a green light to launch its own airstrike.
President Obama has rejected the Israeli call for a red line at that point. But in a speech to the United Nations on Sept. 25, he repeated his position that the United States would work to prevent Iran from gaining nuclear weapons. Mr. Obama’s Republican challenger, Mitt Romney, has been sharply critical of the president for not taking a tough enough line on Iran, and for not supporting Israel strongly enough.
Iran Has Agreed to Talks, Say U.S. Officials
In October, The New York Times reported that the United States and Iran had agreed in principle for the first time to one-on-one negotiations over Iran’s nuclear program, according to Obama administration officials, setting the stage for what could be a last-ditch diplomatic effort to avert a military strike on Iran.
Iranian officials have insisted that the talks wait until after the presidential election, a senior administration official said, telling their American counterparts that they want to know with whom they would be negotiating.
In November, a new report by U.N. inspectors asserted that Iran was set to sharply expand its uranium enrichment in an underground plant after installing all the centrifuges it was built for. The report also showed that Iran’s stockpile of its most sensitive nuclear material — which could relatively quickly be processed further to bomb-grade uranium — had grown and was getting closer to an amount that could be sufficient for a nuclear weapon.
The report also said that satellite photographs show Iran has worked for months to alter another site that the agency has long suspected may have been used for weapons-related experiments.
Sanctions Are Having a Deep Impact on Iran
Through the fall of 2012, new reports emerged of the deep impact that current sanctions are having on the Iranian economy, as Iran’s currency sunk sharply.
As the country’s economic woes deepened, Iranian officials worked to drum up interest in what they called a “nine-step plan” to defuse the nuclear crisis by gradually suspending the production of the uranium that would be easiest for them to convert into a nuclear weapon. But the plan requires so many concessions by the West, starting with the dismantling of all the sanctions that are blocking oil sales and setting off the collapse of the Iranian currency, that American officials have dismissed it as unworkable.
On Oct. 15, the European Union toughened its sanctions on Iran, banning trade in sectors like finance, metals and natural gas, and making business transactions in many other areas far more cumbersome.
Background: Iran’s Nuclear History
Iran’s first nuclear program began in the 1960s under the shah. It made little progress, and was abandoned after the 1979 revolution, which brought to power the hard-line Islamic regime. In the mid-1990s, a new effort began, raising suspicions in Washington and elsewhere. Iran insisted that it was living up to its obligations under the Non-Proliferation Treaty, but in 2002, an exile group obtained documents revealing a clandestine program. Faced with the likelihood of international sanctions, the government of Mohammad Khatami agreed in 2003 to suspend work on uranium enrichment and allow a stepped-up level of inspections by the International Atomic Energy Agency while continuing negotiations with Britain, France and Germany.
In August 2005, Mr. Khatami, a relative moderate, was succeeded as president by Mr. Ahmadinejad, a hard-line conservative. The following January, Iran announced that it would resume enrichment work, leading the three European nations to break off their long-running talks. Under the Non-Proliferation Treaty, Iran has the right to enrich uranium, but the atomic energy association called for the program to be halted until questions about the earlier, secret program were resolved.
The Bush Response
The United Nations Security Council voted in December 2006 to impose sanctions on Iran for failing to heed calls for a suspension. In Washington, administration hawks, led by Vice President Dick Cheney, were reported to favor consideration of more aggressive measures, including possible air strikes, while Secretary of State Condoleezza Rice pushed for more diplomacy.
President George W. Bush sided with Ms. Rice, but declared that the United States would not negotiate directly with Iran until it suspended the nuclear research program. Months of inconclusive talks about talks followed.
The situation was muddied in December 2007 when American intelligence agencies issued a new National Intelligence Estimate that concluded that the weapons portion of the Iranian nuclear program remained on hold. That document said that Iran would probably be able to produce a nuclear weapon between 2010 and 2015, while cautioning that there was no evidence that the Iranian government had decided to do so, contradicting the assessment made in 2005. The estimates given by American military officials in April 2010 are roughly in line with the 2007 estimate. But in June, in the run up to a Security Council vote on sanctions, American officials made clear to their diplomatic counterparts that they now think that Iran has revived elements of its program to design nuclear weapons that the 2007 assessment concluded had gone dormant.
In 2008, President Bush deflected a secret request by Israel for specialized bunker-busting bombs it wanted for an attack on Iran’s main nuclear complex and told the Israelis that he had authorized new covert action intended to sabotage Iran’s suspected effort to develop nuclear weapons, according to senior American and foreign officials.
The White House denied Israel’s request to fly over Iraq to reach Iran’s major nuclear complex at Natanz, American officials said, and the Israelis backed off their plans, at least temporarily. But the tense exchanges also prompted the White House to step up intelligence-sharing with Israel and brief Israeli officials on new American efforts to subtly sabotage Iran’s nuclear infrastructure.
The Obama Response
After years of conflict between Iran and President George W. Bush, President Obama spent his first years in office trying to engage Iran diplomatically, only to see Tehran back away from a tentative agreement to ship some uranium out of the country for enrichment.
On Sept. 9, 2009, American intelligence agencies concluded that Iran had created enough nuclear fuel to make a rapid, if risky, sprint for a nuclear weapon. But new intelligence reports delivered to the White House said that the country has deliberately stopped short of the critical last steps to make a bomb.
In late September 2009, Mr. Obama, along with Prime Minister Gordon Brown of Britain and President Nicolas Sarkozy of France, revealed the existence of a secret underground plant near Qom. American officials said they had been tracking the project for years, but that the president decided to make public the American findings after Iran discovered that the secrecy surrounding the project had been breached.
Talks were then held between Iran and the five permanent members of the United Nations Security Council — the United States, Russia, China, Britain and France — as well as Germany, and led by the European Union‘s foreign policy chief, Javier Solana. At the talks, Iran agreed in principle to export most of its enriched uranium for processing, a step that would have bought more time for negotiations by reducing the amount of potential bomb-making material in Iran’s hands for up to a year.
The news raised a tumult in Iran, with conservative politicians arguing that the West could not be trusted to return the uranium. Shortly after the accord was announced, Iran began raising objections and backtracking. On Oct. 29, Iran told the U.N.’s chief nuclear inspector that it was rejecting the deal.
A 2010 Report Raises Questions
In February 2010, the United Nations’ nuclear inspectors declared for the first time that they had extensive evidence of “past or current undisclosed activities” by Iran’s military to develop a nuclear warhead, an unusually strongly worded conclusion likely to accelerate Iran’s confrontation with the United States and other Western countries.
The report, the first under the new director general of the International Atomic Energy Agency, Yukiya Amano, also concluded that the nation’s weapons-related activity apparently continued “beyond 2004.”
Following the agency’s announcement, Russia said that it was “very alarmed” by Iran’s unwillingness to cooperate with the I.A.E.A. And in late March, a Russian official disclosed that Russian and Chinese envoys had pressed Iran’s government to accept a United Nations plan on uranium enrichment during meetings in Tehran earlier in the month but that Iran had refused, leaving “less and less room for diplomatic maneuvering.”
Questions of Iran’s sincerity were again raised by its announcement on May 17 of an agreement negotiated by Turkey and Brazil that could offer a short-term solution to its ongoing nuclear standoff with the West, or prove to be a tactic aimed at derailing efforts to bring new sanctions against Tehran.
The deal called for Iran to ship 2,640 pounds of low enriched uranium to Turkey, where it would be stored. In exchange, after one year, Iran would have the right to receive about 265 pounds of material enriched to 20 percent from Russia and France.
The next day, Secretary of State Hillary Rodham Clinton announced that a deal had been struck with other major powers, including Russia and China, to impose new sanctions on Iran, a sharp repudiation of the agreement between Iran and Turkey.
A New Round of SanctionsIn June 2010, after months of lobbying by the Obama administration and Europe, the U.N. Security council voted to impose a new round of sanctions on Iran, the fourth such move. But the measures did little to overcome widespread doubts that they — or even the additional steps pledged by American and European officials — would accomplish the Council’s longstanding goal: halting Iran’s production of nuclear fuel.
The new resolution, hailed by President Obama as delivering “the toughest sanctions ever faced by the Iranian government,” took months to negotiate and major concessions by American officials, but still failed to carry the symbolic weight of a unanimous decision. Twelve of the 15 nations on the council voted for the measure, while Turkey and Brazil voted against it and Lebanon abstained.
After the Obama administration imposed additional sanctions on more than a dozen Iranian companies and individuals with links to the country’s nuclear and missile programs, the European Union followed suit with what it called “inevitable” new measures against Tehran.
The main thrust of the sanctions is against military purchases, trade and financial transactions carried out by the Islamic Revolutionary Guards Corps, which controls the nuclear program and has taken a more central role in running the country and the economy.
The United States had sought broader measures against Iran’s banks, insurance industry and other trade, but China and Russia were adamant that the sanctions not affect Iran’s day-to-day economy.
In late November, a trove of diplomatic documents obtained by Wikileaks showed deep concern among Iran’s neighbors over its nuclear program and revealed that American officials believed Tehran had obtained advanced missiles from North Korea that could let it strike at Western European capitals and Moscow. It also provided a detailed look at how President Obama had assembled support for tough sanctions that had eluded President George W. Bush.
In January 2011, Secretary of State Hillary Rodham Clinton said that international sanctions had slowed Iran’s nuclear program, and the restrictions seem to have disrupted sectors of the economy, particularly banking and export-related industries.
A Nuclear ‘Trigger’
An I.A.E.A. report issued in February 2011 listed seven outstanding questions about work Iran apparently conducted on warhead design. The documents in the hands of the agency raise questions about work on how to turn uranium into bomb fuel, how to cast conventional explosives in a shape that can trigger a nuclear blast, how to make detonators, generate neutrons to spur a chain reaction, measure detonation waves and make nose-cones for missiles.
The report gave new details for all seven of the categories of allegations. The disclosure about the atomic trigger centered on a rare material — uranium deuteride , a form of the element made with deuterium, or heavy hydrogen. Nuclear experts say China and Pakistan appear to have used the material as a kind of atomic sparkplug.
The report said it had asked Iran about evidence of “experiments involving the explosive compression of uranium deuteride to produce a short burst of neutrons” — the speeding particles that split atoms in two in a surge of nuclear energy. In a bomb, an initial burst of neutrons is needed to help initiate a rapid chain reaction.
Harold M. Agnew, a former director of the Los Alamos weapons laboratory, said the compression of uranium deuteride suggested work on an atomic trigger.
The agency’s disclosure about Iran’s alleged use of uranium deuteride also suggests another possible connection between Tehran’s program and Abdul Qadeer Khan, the rogue Pakistani engineer who sold nuclear information.
A famous photograph of Dr. Khan, whom Pakistan has released from house arrest in Islamabad, shows him in front of the schematic diagram of an atom bomb on a blackboard. A pointer to the bomb’s center is labeled uranium deuteride.
The report may also gave fresh charges on the design of missile warheads. Documentary evidence, it said, suggested that Iran had conducted “studies involving the removal of the conventional high explosive payload from the warhead of the Shahab-3 missile and replace it with a spherical nuclear payload.”
The Shahab-3 is one of Iran’s deadliest weapons, standing 56 feet tall. In parades, Iran has draped them with banners reading, “Wipe Israel off the map.”
A U.N. Report Rekindles the Nuclear Debate
In November 2011, the International Atomic Energy Agency released a trove of evidence that they said makes a “credible” case that “Iran has carried out activities relevant to the development of a nuclear device” at Parchin and that the project may still be under way.
The report, the harshest judgment that United Nations weapons inspectors had ever issued in their decade-long struggle to pierce the secrecy surrounding the Iranian program, rekindled a debate among the Western allies and Israel about whether increased diplomatic pressure, sanctions, sabotage or military action could stop Iran’s program.
In an effort to thwart Iran’s nuclear program, the United States and the European Union took significant steps to cut Iran off from the international financial system, announcing coordinated sanctions aimed at its central bank and commercial banks. In addition, the United States also imposed sanctions on companies involved in Iran’s nuclear industry, as well as on its petrochemical and oil industries, adding to existing measures that seek to weaken the Iranian government by depriving it of its ability to refine gasoline or invest in its petroleum industry.
In retaliation for the sanctions, Iran vowed to block the Strait of Hormuz, a vital oil transit point. Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, said that the United States would “take action and reopen the strait,” which could be accomplished only by military means, including minesweepers, warship escorts and potentially airstrikes.
By February 2012, the sanctions imposed by the West appeared to be taking a toll. Iran’s economy was showing further signs of strain, with the government looking for ways to avoid the use of dollars in international oil trade, new reports of problems importing food, and a Gallup poll suggesting a majority of Iranians were worried about financial pain from the penalties already imposed. In addition, a flurry of aggressive gestures — attacks on Israelis attributed to Iran; President Mahmoud Ahmadinejad’s renewed posturing over Iran’s latest nuclear advance; and the threats of cutting off oil sales from six European countries — suggested that Iranian leaders were responding frantically, and with increasing unpredictability, to the sanctions.
Another Report Says Iran Close to Producing Nuclear Fuel
On Feb. 24, United Nations nuclear inspectors reported that Iran was moving rapidly to produce nuclear fuel at a deep underground site that Israel and the United States have said is virtually invulnerable to attack.
The report by the International Atomic Energy Agency indicated that for the first time Iran had begun producing fuel inside the new facility in a mountain near the holy city of Qum. The agency’s inspectors found in their visits over the past three months that Iran has tripled its production capacity for a type of fuel that is far closer to what is needed to make the core of a nuclear weapon.
American officials insist that Iran’s progress has been halting at best, and the report also shows that despite Iran’s repeated boasts, it is still having trouble deploying significant amounts of next-generation equipment to make fuel. The United States also argues that Iran’s program has a number of vulnerabilities should it decide to develop a bomb. American intelligence officials say they do not believe Iranian leaders have made that decision, though Israeli and British intelligence disagree.
On Feb. 28, Iran called for negotiations on a treaty banning nuclear weapons and condemned their production or possession as “a great sin.
Speculation Rises About an Israeli Attack
Speculation that Israel might attack Iran intensified in early 2012 as tensions between the countries escalated.
Tensions flared in February when Israeli officials blamed Iran in two separate attacks. On Feb. 13, Israeli Embassy personnel were targeted by bombers in the capitals of Georgia and India, injuring four people, including an Israeli diplomat’s wife. The embassy blasts used methods that were similar to attacks on Iranian nuclear scientists in recent years, for which Iran has blamed Israel. The next day, a series of explosions rocked a residential neighborhood in Bangkok, wounding several people. Thai authorities found a cache of bombs in a rented house and captured two men who carried Iranian passports. Evidence was accumulating that the bombings were part of a single plot, for which Israel has blamed Iran. Iranian officials have denied any involvement.
Should Israel decide to launch a strike on Iran, its pilots would have to fly more than 1,000 miles across unfriendly airspace, refuel in the air en route, fight off Iran’s air defenses, attack multiple underground sites simultaneously — and use at least 100 planes.
That was the assessment of American defense officials and military analysts close to the Pentagon, who said that an Israeli attack meant to set back Iran’s nuclear program would be a huge and highly complex operation. They described it as far different from Israel’s “surgical” strikes on a nuclear reactor in Syria in 2007 and Iraq’s Osirak reactor in 1981.
In a sign of rising American concern, Tom Donilon, the national security adviser, met with Prime Minister Benjamin Netanyahu of Israel in Jerusalem on Feb. 19, and Gen. Martin E. Dempsey warned on CNN that an Israeli strike on Iran right now would be “destabilizing.” Similarly, the British foreign secretary, William Hague, told the BBC that attacking Iran would not be “the wise thing” for Israel to do “at this moment.”
Enforcing Sanctions Amid Threats of Retaliation
In late January 2012, the 27 nations of the Union Under the deal, E.U. members agreed not to sign new oil contracts with Iran and to end existing ones by July 1, according to a statement from European foreign ministers. The embargo covered imports of crude oil, petroleum products and petrochemical products. It also covered the export of key equipment and technology for the sector. The assets of the Iranian central bank within the E.U. were frozen with limited exemptions to permit the continuation of legitimate trade.
In early February, the Obama administration moved to enforce tightened sanctions, freezing all property of the Central Bank of Iran, other Iranian financial institutions and the Iranian government in the United States. The new restrictions also raised new warnings to financial institutions in other nations that they could face big penalties in the United States if they did business with Iran’s central bank. In addition, the Senate Banking Committee unanimously approved a new regimen of anti-Iran sanctions that would for the first time threaten to punish the global financial telecommunications network that nearly all banks rely on to conduct their daily business. Expulsion from the network — the Society for Worldwide Interbank Financial Telecommunication — would deny to Iran many billions of dollars in revenue from abroad that is routinely routed into its domestic banking system.
In response to the sanctions, Ayatollah Ali Khamenei, Iran’s supreme leader, vowed to retaliate, warning that the United States in particular would face severe damage to its interests if any strike were carried out against its nuclear sites.
The pointed remarks by Mr. Khamenei were the most public response by him to mounting tension between Western powers and Iran. They came amid increasing concern among American officials that Israel may soon strike at Iran's nuclear facilities. In early February, The Washington Post reported that Defense Secretary Leon E. Panetta believed there was a “strong likelihood” that Israel would strike Iran in April, May or June.
A Scientist's Death Deepens Fury at Israel and the U.S.
In January 2012, as tensions increased over Iran's nuclear program and belligerence toward the West mounted, Iran reported that an Iranian nuclear scientist died in what was termed a “terrorist bomb blast” in northern Tehran when an unidentified motorcyclist attached a magnetic explosive device to the scientist's car. It was the fourth such attack reported in two years and, as after the previous incidents, Iranian officials indicated that they believed the United States and Israel were responsible.
The next day, Iran expressed deepening fury at Israel and the United States over the scientist's death, and signaled that its Islamic Revolutionary Guards Corps might carry out revenge assassinations.
Israeli officials, who regard Iran as their country's main enemy, have not categorically denied any role in the killing, which came against a backdrop of growing pressure on Iran over its disputed nuclear program.
A Second Uranium Enrichment SiteAlso in January 2012, Iran's top nuclear official announced defiantly that the country was on the verge of starting production at its second major uranium enrichment site. The new facility is buried deep underground on a well-defended military site and is considered far more resistant to air strikes than the existing enrichment site at Natanz, limiting what Israeli officials, in particular, consider an important deterrent to Iran's nuclear aims
The opening of the plant does not significantly affect estimates of how long it could take Iran to produce a nuclear weapon, if that is its true intention. The new facility has been inspected regularly, and unless the Iranians barred inspectors or managed to deceive them, any effort to produce uranium at bomb-grade levels would most likely be detected. American officials have estimated that they would have six months to a year to react, if needed, before the enrichment was completed.
But if it came to that, satellite photographs showed that the new plant is surrounded by anti-aircraft guns, and the mountainous setting was designed to make a bombing campaign nearly impossible.
The C.I.A., according to current and former officials, has repeatedly tried to derail Iran’s uranium enrichment program by covert means, including introducing sabotaged parts into Iran’s supply chain.
In addition, the agency is believed to have encouraged some Iranian nuclear scientists to defect, an effort that came to light in 2010 when a scientist, Shahram Amiri, who had come to the United States, claimed to have been kidnapped by the C.I.A. and returned to Iran. (Press reports say he has since been arrested and tried for treason.) A former deputy defense minister, Ali-Reza Asgari, disappeared while visiting Turkey in 2006 and is widely believed to have defected, possibly to the United States.
After Rounds of Talks, Little Progress
In March 2012, the United States and other global powers announced that they had accepted an offer to resume talks about Iran’s nuclear program that broke off in stalemate more than a year before.
In mid-April, diplomats from Iran, the United States and other world powers met in Istanbul. The talks went surprisingly well and were something of a turning point in the American thinking about Iran. At the meeting, Iranian negotiators seemed more flexible and open to resolving the crisis, even though no agreement was reached.
In May, a round of talks was held in Baghdad, but they ended with no clear signs of progress. During the talks, Iran was known to be unhappy about proposals to address urgent concerns, including a freeze on its enrichment of uranium that could be converted to bomb-grade fuel, because of what the Iranians suggested was an insufficient easing of punishing sanctions.
The Baghdad talks began a day after Tehran signaled willingness to allow potentially intrusive international inspections of secret military facilities, raising expectations that it was searching for a diplomatic solution to the standoff, although Western officials discounted the likelihood of an imminent breakthrough. And in fact, after follow up talks, the International Atomic Energy Agency expressed disappointment at what it said were new hurdles raised by Iran.
In June, diplomats from Iran and six world powers met in Moscow. After two days of fruitless talks, negotiators for the United States and other major powers did not even schedule another high-level meeting with Iran, committing only to a lower-level session in July to go over the technical details of a proposal to suspend the enrichment of uranium that Iran has already rejected in principle.
Dennis B. Ross, a former senior White House adviser on Iran, said he believed the negotiations had become a trap, allowing Iran to continue enriching nuclear fuel while the two sides failed to agree on even interim measures to slow the Iranian program. The major powers, he said, should scrap the step-by-step approach in favor of a comprehensive deal that would test Iran’s sincerity, but could also hasten a military confrontation.
Other critics were even blunter, labeling the talks a “charade” and demanding that Congress pass another round of sanctions against Iran. Before the talks, 44 Republican and Democratic senators sent a letter to President Obama urging him to abandon the negotiations if the Moscow meeting failed to produce any concessions from Iran.
Hoping That New Sanctions Will Change Iran’s Course
In the summer of 2012, the Obama administration and its European allies imposed sweeping new sanctions meant to cut Iran off from the global oil market. Many experts regard it as the best hope for forcing Iran to change its course.
In late June, the United States imposed sanctions that could punish any foreign country that buys Iranian oil. However, it issued six-month exemptions to 20 importers of Iranian oil who had significantly cut their purchases, including China, which has openly opposed the pressure on Iran.
On July 1, the European Union put in place a complete embargo of oil imports from Iran, which was the Continent’s sixth-biggest supplier of crude in 2011.
Even before these steps, Iran conceded that its oil exports were down 20 to 30 percent. Its currency had plunged more than 40 percent against the dollar since 2011. But so far the escalating sanctions, which the Bush administration started and the Obama administration has intensified, have failed in their central goal of forcing Iran’s mullahs to stop enriching uranium.
Iran responded to the new sanctions with a series of defiant steps, announcing legislation intended to disrupt traffic in the Strait of Hormuz, a vital Persian Gulf shipping lane, and testing missiles in a desert drill clearly intended as a warning to Israel and the United States.
A Target of Cyber attacks
Over the last few years, Iran has become the target of a series of notable cyber attacks, some of which were linked to its nuclear program. According to an article in The New York Times in June 2012, during President Obama‘s first few months in office, he secretly ordered increasingly sophisticated attacks on Iran’s computer systems at its nuclear enrichment facilities, significantly expanding America’s first sustained use of cyber weapons.
The best known of the cyberweapons was Stux net, a computer worm, or malicious computer program, that turned up in industrial programs around the world in 2009. Stuxnet, which had been developed by the United States and Israel, appears to have wiped out nearly 1,000 of the 5,000 centrifuges Iran had spinning at the time to purify uranium.
In May 2012, a data-mining virus called Flame had penetrated the computers of high-ranking Iranian officials, sweeping up information from their machines. In a message posted on its Web site, Iran’s Computer Emergency Response Team Coordination Center warned that the virus was potentially more harmful than Stuxnet. In contrast to Stuxnet, Flame appeared to be designed not to do damage but to secretly collect information from a wide variety of sources.
Inspectors Report New Centrifuges
The report by the International Atomic Energy Agency, the last to be issued before the American presidential election, lays out in detail how Iran has used the summer to double the number of centrifuges installed deep under a mountain near the holy city of Qum, while cleansing another site where the agency has said it suspects that the country has conducted explosive experiments that could be “relevant” to the production of a nuclear weapon. Based on satellite photographs, the I.A.E.A. said the cleanup has been so extensive that it would “significantly hamper” the ability of inspectors to understand what kind of work took place there.
The report confirmed that a recent boast by Iran’s supreme leader, Ayatollah Ali Khamenei, that Iran had added nearly 1,000 centrifuges to the underground site was accurate. But it left open the question of what, exactly, Mr. Khamenei and other Iranian leaders intended to do with those machines, and whether, by racing ahead with construction, they were seeking negotiating advantage or trying to gain the capability to build a bomb before sanctions, sabotage or military action could stop them.
On Aug. 30, Ayatollah Khamenei reiterated his position that Iran is not seeking an atomic bomb, and he criticized what he called the hypocrisy of the American-Israeli campaign against Iran. In a speech to the 120-member Nonaligned Movement meeting in Tehran, the ayatollah also reminded the delegates that the United States is the only country that has ever used a nuclear weapon and that Israel has its own unacknowledged stockpile of nuclear weapons.
With senior Obama administration officials warning Prime Minister Benjamin Netanyahu and his cabinet that a military strike on Iran’s nuclear sites would be counterproductive, the report offers arguments for both sides in the debate.
The Israelis in favor of military action, led by Defense Minister Ehud Barak, the most outspoken proponent of moving quickly against the Iranian program, will point to evidence that Iran has now installed over 2,100 of the roughly 2,800 centrifuges destined for the underground site, called Fordow. For Mr. Barak, that is evidence that the “zone of immunity” he has warned about — the point at which Iran will be able to produce nuclear fuel from a site invulnerable to attack — will be reached in a matter of weeks.
But American officials urging caution will find plenty in the report to bolster their view as well. Only a third of the centrifuges at Fordow are actually operating, the inspectors reported, leaving open the question of whether Iran has run into technical difficulties or has made a political decision not to tempt its adversaries by rushing ahead in moving production of fuel to its best-protected facility. And while the agency’s statistics show that Iran has, since February, doubled its stockpile of fuel enriched to 20 percent purity — a level that bomb experts say could be converted to bomb grade in a matter of months — it still does not possess enough of that fuel to produce a complete nuclear weapon. Most of its stockpile is composed of a lower-enriched fuel that would take considerably longer to make useful in a weapon.
The progress cited in the report could make it harder to win a diplomatic deal. Under an offer that the United States and its Western allies, along with Russia, presented to Iran privately in late spring 2012, Tehran would be allowed to retain some enrichment capability if it turned over its entire stockpile of 20 percent-enriched uranium and answered the questions posed by international inspectors about evidence that it has worked on a weapon. Though Iranian officials have privately expressed some interest in the plan, the deal has gone nowhere, and no new negotiating sessions are scheduled, American officials say.
