Tag Archives: Iran nuclear energy

By Hook or By Crook (or Both): How Iran Beats US Sanctions

Persian Gulf waters off Iraq have become a new, important waypoint for Iranian oil smugglers looking to avoid U.S. sanctions…Iranian tankers now regularly transfer crude to other ships just miles offshore the major Iraqi port of Al Faw, according to the officials. The oil is then mixed with cargoes from other places to disguise its origin, and it eventually ends up on sale in world markets, they say.


In one example from March 2020,  according to a shipping manifest reviewed by The Wall Street Journal, 230,000 barrels of oil from the state-run National Iranian Oil Co. were transferred to a vessel moored in Iraqi waters. The cargo was blended with Iraqi oil and passed to other ships, according to people familiar with the operation. The ultimate destination of the oil wasn’t clear.

The people familiar with the transfer said the operation was part of an increasingly common and lucrative business that involves transferring and mixing cargoes with other vessels multiple times and then selling the oil with documents that declare it is as Iraqi. Iraqi oil can be sold at a significant premium to oil of Iranian origin.

Iran has increasingly tried to find ways to get its crude to market despite the U.S. sanctions. Iran’s daily crude and condensates exports averaged 827,000 barrels a day in the first six months of this year, according to U.S. shipping-information company TankerTrackers.com. That is up 28% from the previous six months, but far below the level of 2.7 million barrels a day in May 2018 before the sanctions.

“We While some of Iran’s oil exports go to countries not aligned with the U.S., such as Syria and China, they often pass through allies such as the United Arab Emirates or Iraq, where their origin is being concealed, according to U.S. officials.

Excerpt from Sarah McFarlane and Benoit Faucon, Iraq Emerges as Hurdle to Enforcing Iran Oil Sanctions, WSJ, Oct. 24, 2020

How Iranian Oil Escapes US Sanctions

 At least two tankers have ferried Iranian fuel oil to Asia in February 2019 despite U.S. sanctions against such shipments, according to a Reuters analysis of ship-tracking data and port information, as well as interviews with brokers and traders.  The shipments were loaded onto tankers with documents showing the fuel oil was Iraqi. But three Iraqi oil industry sources and Prakash Vakkayil, a manager at United Arab Emirates (UAE) shipping services firm Yacht International Co, said the papers were forged.  The people said they did not know who forged the documents, nor when.

“Some buyers…will want Iranian oil regardless of U.S. strategic objectives to deny Tehran oil revenue, and Iran will find a way to keep some volumes flowing,” said Peter Kiernan, lead energy analyst at the Economist Intelligence Unit.  While the United States has granted eight countries temporary waivers allowing limited purchases of Iranian crude oil, these exemptions do not cover products refined from crude, including fuel oil, mainly used to power the engines of large ships. Documents forwarded to Reuters by ship owners say a 300,000 tonne-supertanker, the Grace 1, took on fuel oil at Basra, Iraq, between Dec. 10 and 12, 2018. But Basra port loading schedules reviewed by Reuters do not list the Grace 1 as being in port during those dates.  One Iraqi industry source with knowledge of the port’s operations confirmed there were no records of the Grace 1 at Basra during this period. 

Grace 1 oil tanker

Reuters examined data from four ship-tracking information providers – Refinitiv, Kpler, IHS Markit and Vessel Finder – to locate the Grace 1 during that time. All four showed that the Grace 1 had its Automatic Identification System (AIS), or transponder, switched off between Nov. 30 and Dec. 14, 2018, meaning its location could not be tracked.  The Grace 1 then re-appeared in waters near Iran’s port of Bandar Assaluyeh, fully loaded, data showed. The cargo was transferred onto two smaller ships in UAE waters in January, from where one ship delivered fuel oil to Singapore in February 2019.  Shipping documents showed about 284,000 tonnes of fuel oil were transferred in the cargoes tracked by Reuters, worth about $120 million at current prices…

One of those vessels, the 130,000 tonne-capacity Kriti Island, offloaded fuel oil into a storage terminal in Singapore around Feb. 5 to 7. Reuters was unable to determine who purchased the fuel oil for storage in Singapore.  The Kriti Island is managed by Greece’s Avin International SA… Avin International’s Chief Executive Officer George Mylonas told Reuters. Mylonas confirmed the Kriti Island took on fuel oil from the Grace 1.There is no indication that Avin International knowingly shipped Iranian fuel oil. Mylonas said his firm had conducted all necessary due diligence to ensure the cargo’s legitimate origin….

Kriti Island oil tanker

Excerpts from Roslan Khasawneh et al, Exclusive: How Iran fuel oil exports beat U.S. sanctions in tanker odyssey to Asia, Reuters, Mar. 20, 2019

The Sanctions Busters: Germany and France

The steps by Europe’s most powerful countries are part of their campaign to salvage the 2015 Iran nuclear deal after President Trump withdrew the U.S. in May. Their goal is to help European companies continue some business activity with Iran despite sweeping new U.S. sanctions on the country and any company that does business with it.

France or Germany will host the corporation that would handle the payments channel, the diplomats said. If France hosts it, a German official will head the corporation and vice versa. Both countries will help fund the corporation.  The payments channel, known as a special purpose vehicle, or SPV, would use a system of credits to facilitate compensation for goods traded between Iran and Europe—allowing some trade to proceed without the need for European commercial banks to make or receive payments to Iran.

U.S. pressure on Austria and Luxembourg recently prompted those countries to reject European Union requests to host it, raising the prospect that the initiative might collapse, the diplomats said.  The company would be owned directly by participating European governments—an arrangement intended to dissuade the U.S. from directly targeting it with sanctions, diplomats said.

Laurence Norman , France and Germany Step In to Circumvent Iran Sanctions, WSJ, Nov. 26, 2018

Unleashing Nuclear Power – Iran

China was expected to build two nuclear power plants for Iran as part of the country’s new nuclear direction under the controversial nuclear deal that was signed July 15, 2015. The plants were set to be located on the Makran coast, near the neighboring Gulf of Oman, Iran’s Atomic Energy Organization head Ali Akbar Salehi announced on July 22, 2015.

Uninhibited by sanctions, Iran announced plans for four new nuclear power plants. Chinese contractors will be building two of the four planned. “We will simultaneously launch construction of four new nuclear power plants in the country in the next two to three years,” Salehi said, according to Indo-Asian News Service. “We plan to engage more than 20,000 workers and engineers in this large-scale construction.”

When it comes to United Nations sanctions, China had always been an advocate for Iran, along with Russia, generally opposing Washington’s proposed restrictions. On July 20, 2015, the United Nations adopted the nuclear deal between Tehran and Washington, after the “P5+1” countries — the U.S., Britain, France, Russia, China and Germany — unanimously approved it, also voting to lift a series of economic sanctions that were previously imposed on Iran.

China has played a unique, hands-on role in the nuclear deal involving Iran’s Arak reactor, which has been described previously as a “pathway” to nuclear weapons for Iran.

“China has put forward the idea of the modification of the Arak heavy water reactor. … This is the unique role China has played in resolving the Iranian nuclear issue,” Chinese Foreign Minister Wang Yisaid in a statement…..  [The nuclear deal]  has also opened up a door to increased business opportunity in Iran, particularly for China.  Following the announcement of the landmark deal, Wang said that China played a pivotal role in negotiations, and he expressed hope that Iran would take part in China’s “one belt, one road” ambition to revive the Silk Road route.

Excerpts from Michelle FlorCruz, Iran Nuclear Deal: China To Build 2 Nuclear Power Plants For Islamic Republic Following Landmark Agreement, International Business Times, July 22, 2015

Full text of Iran Nuclear Deal Signed July 15, 2015
Joint Comprehensive Plan of Action
Annex I: Nuclear-related commitments
Annex II: Sanctions-related commitments
Attachments to Annex II
Annex III: Civil nuclear cooperation
Annex IV: Joint Commission
Annex V: Implementation Plan

Nuclear Capability of Iran – Natanz, Fordow, Parchin

One [of the problems] is the ambiguity about what rights the Iranians will have to continue nuclear research and development. They are working on centrifuges up to 20 times faster than today’s, which they want to start deploying when the agreement’s [the currently negotiated agreement between Iran and United States/Europe]  first ten years are up. The worry is that better centrifuges reduce the size of the clandestine enrichment facilities that Iran would need to build if it were intent on escaping the agreement’s strictures.

That leads to the issue on which everything else will eventually hinge. Iran has a long history of lying about its nuclear programme. It only declared its two enrichment facilities, Natanz and Fordow, after Western intelligence agencies found out about them. A highly intrusive inspection and verification regime is thus essential, and it would have to continue long after other elements of an agreement expire. Inspectors from the IAEA would have to be able to inspect any facility, declared or otherwise, civil or military, on demand…

For a deal to be done in June 2015, Iran will have to consent to an [intrusive] inspection regime. It will also have to answer about a dozen questions already posed by the IAEA about the “possible military dimensions” of its nuclear programme. Yet on March 23, 2015Yukiya Amano, the agency’s director, said that Iran had replied to only one of those questions. Parchin, a military base which the IAEA believes may have been used for testing the high-explosive fuses that are needed to implode, and thus set off, the uranium or plutonium at the core of a bomb, remains out of bounds. Nor has the IAEA been given access to Mohsen Fakhrizadeh, the physicist and Revolutionary Guard officer alleged to be at the heart of the weapons development research. The IAEA’s February 19, 2015 report on Iran stated that it “remains concerned about the possible existence…of undisclosed nuclear-related activities…including activities related to the development of a nuclear payload for a missile.”

Excerpts from, The Iran Nuclear Talks: Not Yet the Real Deal, Economist, Apr. 4, 2015, at 43

Iran Nuclear Talks: the Khamenei Card

On July 7, 1014 as critical nuclear negotiations got underway in Vienna between Iran, the United States, Europe, Russia and China, Khamenei (Iranian Supreme Leader) started talking hard numbers.  The Supreme Leader’s remarks were unprecedented both because they represented a blatant intervention from his perch in Tehran in the super-sensitive talks in Vienna, and because they relayed confidential technical details that had not been aired publicly before by Iranian officials.

The moment could not be more critical. An agreement is supposed to be reached before July 20, 2014 that will rein in the threat of Iran acquiring nuclear weapons and end or curtail the Western sanctions that have put so much pressure on Tehran. Failure to reach an accord will add yet more potentially apocalyptic uncertainties to the Middle Eastern scene…

The Supreme Leader started talking about SWUs, which it is fair to say few Iranians, or for that matter Americans, Europeans, Russians or Chinese ever have heard of.  In this context the acronym stands for “separative work units,” which relates directly to Iran’s ability to enrich uranium to levels that might feed into nuclear weapons. SWU defines the capability derived from the number of uranium-enriching centrifuges and their efficiency. For example one thousand AR1 centrifuges with the efficiency of 0.9 translates into 900 SWU, whereas 225 AR2 centrifuges with an efficiency of 4 translates into 900 SW…

“They want us to be content with 10,000 SWUs,” he said. That is, he estimates the bottom line the West will accept. “But they have started from 500 and 1000 SWUs,” he added. “Our people say that we need 190,000 SWUs,” he went on. That’s a big spread to try to close.  Khamenei then raised the problem of American and European objections to the more-or-less bomb-proof underground facility Iran has built at Fordo, where much of its enrichment goes on. “They emphasize Fordo because they cannot get to it,” said Khamenei. “They say you must not have a place which we cannot strike. Isn’t this ridiculous?”

Last December [2013] Khamenei said publicly he would not interfere in the negotiations and would leave the details to the diplomats. Now it appears he is playing a more shadowy game, either dictating terms to the Iranian team in Vienna or, perhaps, providing them the cover they need to stand firm.

A source close to the negotiations told IranWire that the numbers Khamenei cited are precisely what American negotiators have put on the table, and constitute one of the confidential topics being discussed over the past few months. Two days before Khamenei spoke, Under Secretary of States for Political Affairs Wendy Sherman, the senior American negotiator, said that Iran must end up with a fraction of the centrifuges it currently runs, but she did not cite any numbers.

The source said that Khamenei’s statements are technically significant, and are in line with the terms of the negotiations, which deal with SWUs rather than the number of centrifuges as such.

According to a European diplomat who is a member of his country’s nuclear negotiating team, the accuracy of the numbers leaked by Khamenei is both astonishing and worrisome, because he is limiting publicly the concessions that might be made by Iranian President Hassan Rouhani’s team….

It is clear Khamenei wants to leave no doubt about his regime’s red lines in the negotiations…  But Khamenei doesn’t see this crisis only in terms of nukes. For the West, he says, the nuclear issue “is just an excuse” to pressure Iran, he said. “If it is not the nuclear issue they will come up with another excuse—human rights, women’s right, etc.”

Excerpts from Reza HaghighatNejad, Iran Supreme Leader Spills the Nuke Talk Secrets, Daily Beast, July 9, 2014

Iran Defeats Sanctions through Chinese Networks

A Chinese citizen faces U.S. criminal charges that he conspired to export to Iran products that could be used in that country’s nuclear program, the U.S. Justice Department.  Sihai Cheng supplied thousands of parts that have nuclear applications to Eyvaz, a company involved in Iran’s nuclear weapons program, in violation of U.S. sanctions on Iran, federal prosecutors said.

Sihai Cheng of Shanghai and Seyed Abolfazl Shahab Jamili of Tehran allegedly plotted between 2009 and 2011 to send pressure measuring sensors, or transducers, ordered from MKS Instruments Inc. in Andover, USA, to Eyvaz Technic Manufacturing Co., a Tehran-based business that has supplied parts to Iranian nuclear facilities.  Transducers are used in commercial products, but can also be used in gas centrifuges to convert natural uranium into a form suited for nuclear weapons, the indictment states.

Prosecutors said MKS Instruments sent the transducers to China without knowing they were ultimately bound for Iran.

In February 2009, Jamili wrote to Cheng that Eyvaz Technic was seeking to obtain a type of transducer. Eyvaz has “supplied parts for Iran’s development of nuclear weapons,” the indictment states.  After receiving the 2009 e-mail, Cheng allegedly plotted with unidentified coconspirators at MKS-Shanghai, a wholly owned Chinese subsidiary of MKS in Andover, to set up front companies to pose as the intended recipients of the materials, which were ordered from the Andover office.  In addition, MKS-Shanghai employees listed other legitimate Chinese companies as recipients in purchase orders sent to Andover, authorities said.  More than 1,000 orders for MKStransducers with a combined value of over $1.8 million were placed between April 2009 and January 2011, the indictment said. Once the parts arrived in China, Cheng had them shipped to Eyvaz, the Iranian company accused of supplying material for Iran’s nuclear enrichment facilities.

Prosecutors wrote that MKS in Andover “unwittingly assisted MKS-Shanghai in fraudulently obtaining an export license for a large quantity of pressure transducers.”  Authorities say there is evidence MKS products reached the Natanz nuclear enrichment facility in Iran, which began operating thousands of gas centrifuges as early as 2007.  “Publicly available photographs of Natanz [with then President Mahmoud Ahmadinejad] show numerous MKS pressure transducers attached to Iran’s gas centrifuge cascades,” the indictment says.

Excerpt from Chinese national indicted in US over exports to Iran,  Reuters, Apr. 4, 2014 and from Travis Andersen and Jennifer Smith, Men accused of sending nuclear supplies to Iran, Boston Globe, Apr. 5, 2014

A Love Affair with Iran: Glencore and Trafigura

Glencore, a commodity trading house run by the billionaire Ivan Glasenberg, traded $659m (£430m) of goods, including aluminium oxide, to Iran last year, the Guardian has established.  The company…has admitted that some of its aluminium oxide ended up in the hands of Iranian Aluminium Company (Iralco).  Trafigura, another commodity trading house, has also admitted to trading an unspecified aluminium oxide (also known as alumina) with Iralco in the past.

The International Atomic Energy Agency has named Iralco as supplying aluminium to Iran Centrifuge Technology Company (Tesa), which is part of the Atomic Energy Organisation of Iran (AEOI). Aluminium oxide is an important material in gas centrifuges used to enrich uranium.  At the time of the Glencore and Trafigura trades with Iralco, it was not illegal or a breach of sanctions to supply Iran with alumina. It is unknown whether Glencore or Trafigura’s alumina passed from Iralco to Tesa, or whether it was used in centrifuge construction.

Since 2006, AEOI has been subject to UN sanctions designed to prevent Iran’s nuclear armament ambitions. Trading with Tesa has been specifically banned under US, EU and UK sanctions since July 2010. Iralco was added to the EU sanctions list in December 2012.  Glencore said it “ceased transactions” with Iralco immediately when it learned of its links with Tesa, and the last trade was in October 2012. “Prior to EU sanctions in December 2012, we were not aware of a link/contract between Iralco and Tesa,” the company said in a statement.  Glencore said it is “reliant on the relevant regulatory bodies/governments to advise us on developments in who we can/can’t do business with”.

Tehran, which some experts say already has enough enriched uranium to make several nuclear weapons, is in the middle of upgrading its stock of more than 10,000 centrifuges. The IAEA said Iran is replacing outdated centrifuges with thousands of more powerful IR-2m models.  Experts at the Institute for Science and International Security (Isis) in London said: “Iran is trying to replace maraging [super-strong] steel end-caps with high strength aluminium end-caps.”  Mark Fitzpatrick, director of Isis’s nonproliferation and disarmament programme, said the new centrifuges could enrich uranium four to five times faster than the existing ones. Iran insists its enriched material is for peaceful use, not for nuclear weapons, but it has refused to allow IAEA inspectors into several of its atomic facilities.

The Guardian has learned that Glencore traded $659m worth of metals, wheat and coal with Iranian entities during 2012. Buried deep in its annual report, one of Glencore’s US affiliates, Century Aluminium, 46% owned by Glencore, states: “During 2012 non-US affiliates of the largest stockholder of the company [Glencore] entered into sales contracts for wheat and coal as well as sale and purchase contracts for metal oxides and metals with Iranian entities, which are either fully or majority owned by the GOI [government of Iran].”…..

Trafigura, which came to global political attention when it was revealed that a licensed independent contractor of a ship it had chartered dumped tonnes of toxic oil slops in Ivory Coast, said: “We can confirm that Trafigura has traded with Iralco in the past. In October 2011, a physical swap agreement was reached whereby Trafigura provided alumina to Iralco in return for aluminium for Trafigura to export worldwide. No deliveries have been made or exports received since new EU sanctions were published in December 2012.

Excerpts, Rupert Neate, Glencore traded with Iranian supplier to nuclear weapon’s programme, Guardian,  Apr. 21, 2013

United States, Iran and the Stuxnet Worm

From his first months in office, President Obama secretly ordered increasingly sophisticated attacks on the computer systems that run Iran’s main nuclear enrichment facilities, significantly expanding America’s first sustained use of cyberweapons, according to participants in the program.  Mr. Obama decided to accelerate the attacks — begun in the Bush administration and code-named Olympic Games — even after an element of the program accidentally became public in the summer of 2010 because of a programming error that allowed it to escape Iran’s Natanz plant and sent it around the world on the Internet. Computer security experts who began studying the worm, which had been developed by the United States and Israel, gave it a name: Stuxnet.  At a tense meeting in the White House Situation Room within days of the worm’s “escape,” Mr. Obama, Vice President Joseph R. Biden Jr. and the director of the Central Intelligence Agency at the time, Leon E. Panetta, considered whether America’s most ambitious attempt to slow the progress of Iran’s nuclear efforts had been fatally compromised.  “Should we shut this thing down?” Mr. Obama asked, according to members of the president’s national security team who were in the room.  Told it was unclear how much the Iranians knew about the code, and offered evidence that it was still causing havoc, Mr. Obama decided that the cyberattacks should proceed. In the following weeks, the Natanz plant was hit by a newer version of the computer worm, and then another after that. The last of that series of attacks, a few weeks after Stuxnet was detected around the world, temporarily took out nearly 1,000 of the 5,000 centrifuges Iran had spinning at the time to purify uranium.

This account of the American and Israeli effort to undermine the Iranian nuclear program is based on interviews over the past 18 months with current and former American, European and Israeli officials involved in the program, as well as a range of outside experts. None would allow their names to be used because the effort remains highly classified, and parts of it continue to this day.  These officials gave differing assessments of how successful the sabotage program was in slowing Iran’s progress toward developing the ability to build nuclear weapons. Internal Obama administration estimates say the effort was set back by 18 months to two years, but some experts inside and outside the government are more skeptical, noting that Iran’s enrichment levels have steadily recovered, giving the country enough fuel today for five or more weapons, with additional enrichment.

Whether Iran is still trying to design and build a weapon is in dispute. The most recent United States intelligence estimate concludes that Iran suspended major parts of its weaponization effort after 2003, though there is evidence that some remnants of it continue.

Iran initially denied that its enrichment facilities had been hit by Stuxnet, then said it had found the worm and contained it. Last year, the nation announced that it had begun its own military cyberunit, and Brig. Gen. Gholamreza Jalali, the head of Iran’s Passive Defense Organization, said that the Iranian military was prepared “to fight our enemies” in “cyberspace and Internet warfare.” But there has been scant evidence that it has begun to strike back.

The United States government only recently acknowledged developing cyberweapons, and it has never admitted using them. There have been reports of one-time attacks against personal computers used by members of Al Qaeda, and of contemplated attacks against the computers that run air defense systems, including during the NATO-led air attack on Libya last year. But Olympic Games was of an entirely different type and sophistication.

It appears to be the first time the United States has repeatedly used cyberweapons to cripple another country’s infrastructure, achieving, with computer code, what until then could be accomplished only by bombing a country or sending in agents to plant explosives. The code itself is 50 times as big as the typical computer worm, Carey Nachenberg, a vice president of Symantec, one of the many groups that have dissected the code, said at a symposium at Stanford University in April. Those forensic investigations into the inner workings of the code, while picking apart how it worked, came to no conclusions about who was responsible.

A similar process is now under way to figure out the origins of another cyberweapon called Flame that was recently discovered to have attacked the computers of Iranian officials, sweeping up information from those machines. But the computer code appears to be at least five years old, and American officials say that it was not part of Olympic Games. They have declined to say whether the United States was responsible for the Flame attack.

Mr. Obama, according to participants in the many Situation Room meetings on Olympic Games, was acutely aware that with every attack he was pushing the United States into new territory, much as his predecessors had with the first use of atomic weapons in the 1940s, of intercontinental missiles in the 1950s and of drones in the past decade. He repeatedly expressed concerns that any American acknowledgment that it was using cyberweapons — even under the most careful and limited circumstances — could enable other countries, terrorists or hackers to justify their own attacks.

“We discussed the irony, more than once,” one of his aides said. Another said that the administration was resistant to developing a “grand theory for a weapon whose possibilities they were still discovering.” Yet Mr. Obama concluded that when it came to stopping Iran, the United States had no other choice.If Olympic Games failed, he told aides, there would be no time for sanctions and diplomacy with Iran to work. Israel could carry out a conventional military attack, prompting a conflict that could spread throughout the region.

The impetus for Olympic Games dates from 2006, when President George W. Bush saw few good options in dealing with Iran. At the time, America’s European allies were divided about the cost that imposing sanctions on Iran would have on their own economies. Having falsely accused Saddam Hussein of reconstituting his nuclear program in Iraq, Mr. Bush had little credibility in publicly discussing another nation’s nuclear ambitions. The Iranians seemed to sense his vulnerability, and, frustrated by negotiations, they resumed enriching uranium at an underground site at Natanz, one whose existence had been exposed just three years before.

Iran’s president, Mahmoud Ahmadinejad, took reporters on a tour of the plant and described grand ambitions to install upward of 50,000 centrifuges. For a country with only one nuclear power reactor — whose fuel comes from Russia — to say that it needed fuel for its civilian nuclear program seemed dubious to Bush administration officials. They feared that the fuel could be used in another way besides providing power: to create a stockpile that could later be enriched to bomb-grade material if the Iranians made a political decision to do so.  Hawks in the Bush administration like Vice President Dick Cheney urged Mr. Bush to consider a military strike against the Iranian nuclear facilities before they could produce fuel suitable for a weapon. Several times, the administration reviewed military options and concluded that they would only further inflame a region already at war, and would have uncertain results.

For years the C.I.A. had introduced faulty parts and designs into Iran’s systems — even tinkering with imported power supplies so that they would blow up — but the sabotage had had relatively little effect. General James E. Cartwright, who had established a small cyberoperation inside the United States Strategic Command, which is responsible for many of America’s nuclear forces, joined intelligence officials in presenting a radical new idea to Mr. Bush and his national security team. It involved a far more sophisticated cyberweapon than the United States had designed before.

The goal was to gain access to the Natanz plant’s industrial computer controls. That required leaping the electronic moat that cut the Natanz plant off from the Internet — called the air gap, because it physically separates the facility from the outside world. The computer code would invade the specialized computers that command the centrifuges.  The first stage in the effort was to develop a bit of computer code called a beacon that could be inserted into the computers, which were made by the German company Siemens and an Iranian manufacturer, to map their operations. The idea was to draw the equivalent of an electrical blueprint of the Natanz plant, to understand how the computers control the giant silvery centrifuges that spin at tremendous speeds. The connections were complex, and unless every circuit was understood, efforts to seize control of the centrifuges could fail.

Eventually the beacon would have to “phone home” — literally send a message back to the headquarters of the National Security Agency that would describe the structure and daily rhythms of the enrichment plant. Expectations for the plan were low; one participant said the goal was simply to “throw a little sand in the gears” and buy some time. Mr. Bush was skeptical, but lacking other options, he authorized the effort.  It took months for the beacons to do their work and report home, complete with maps of the electronic directories of the controllers and what amounted to blueprints of how they were connected to the centrifuges deep underground.  Then the N.S.A. and a secret Israeli unit respected by American intelligence officials for its cyberskills set to work developing the enormously complex computer worm that would become the attacker from within.  The unusually tight collaboration with Israel was driven by two imperatives. Israel’s Unit 8200, a part of its military, had technical expertise that rivaled the N.S.A.’s, and the Israelis had deep intelligence about operations at Natanz that would be vital to making the cyberattack a success. But American officials had another interest, to dissuade the Israelis from carrying out their own pre-emptive strike against the Iranian nuclear facilities. To do that, the Israelis would have to be convinced that the new line of attack was working. The only way to convince them, several officials said in interviews, was to have them deeply involved in every aspect of the program.

Soon the two countries had developed a complex worm that the Americans called “the bug.” But the bug needed to be tested. So, under enormous secrecy, the United States began building replicas of Iran’s P-1 centrifuges, an aging, unreliable design that Iran purchased from Abdul Qadeer Khan, the Pakistani nuclear chief who had begun selling fuel-making technology on the black market. Fortunately for the United States, it already owned some P-1s, thanks to the Libyan dictator, Col. Muammar el-Qaddafi.  When Colonel Qaddafi gave up his nuclear weapons program in 2003, he turned over the centrifuges he had bought from the Pakistani nuclear ring, and they were placed in storage at a weapons laboratory in Tennessee. The military and intelligence officials overseeing Olympic Games borrowed some for what they termed “destructive testing,” essentially building a virtual replica of Natanz, but spreading the test over several of the Energy Department’s national laboratories to keep even the most trusted nuclear workers from figuring out what was afoot.

Those first small-scale tests were surprisingly successful: the bug invaded the computers, lurking for days or weeks, before sending instructions to speed them up or slow them down so suddenly that their delicate parts, spinning at supersonic speeds, self-destructed. After several false starts, it worked. One day, toward the end of Mr. Bush’s term, the rubble of a centrifuge was spread out on the conference table in the Situation Room, proof of the potential power of a cyberweapon. The worm was declared ready to test against the real target: Iran’s underground enrichment plant.

“Previous cyberattacks had effects limited to other computers,” Michael V. Hayden, the former chief of the C.I.A., said, declining to describe what he knew of these attacks when he was in office. “This is the first attack of a major nature in which a cyberattack was used to effect physical destruction,” rather than just slow another computer, or hack into it to steal data…  Getting the worm into Natanz, however, was no easy trick. The United States and Israel would have to rely on engineers, maintenance workers and others — both spies and unwitting accomplices — with physical access to the plant. “That was our holy grail,” one of the architects of the plan said. “It turns out there is always an idiot around who doesn’t think much about the thumb drive in their hand.”

In fact, thumb drives turned out to be critical in spreading the first variants of the computer worm; later, more sophisticated methods were developed to deliver the malicious code.  The first attacks were small, and when the centrifuges began spinning out of control in 2008, the Iranians were mystified about the cause, according to intercepts that the United States later picked up. “The thinking was that the Iranians would blame bad parts, or bad engineering, or just incompetence,” one of the architects of the early attack said.  The Iranians were confused partly because no two attacks were exactly alike. Moreover, the code would lurk inside the plant for weeks, recording normal operations; when it attacked, it sent signals to the Natanz control room indicating that everything downstairs was operating normally. “This may have been the most brilliant part of the code,” one American official said.

Later, word circulated through the International Atomic Energy Agency, the Vienna-based nuclear watchdog, that the Iranians had grown so distrustful of their own instruments that they had assigned people to sit in the plant and radio back what they saw.  “The intent was that the failures should make them feel they were stupid, which is what happened,” the participant in the attacks said. When a few centrifuges failed, the Iranians would close down whole “stands” that linked 164 machines, looking for signs of sabotage in all of them. “They overreacted,” one official said. “We soon discovered they fired people.”

Imagery recovered by nuclear inspectors from cameras at Natanz — which the nuclear agency uses to keep track of what happens between visits — showed the results. There was some evidence of wreckage, but it was clear that the Iranians had also carted away centrifuges that had previously appeared to be working well.  But by the time Mr. Bush left office, no wholesale destruction had been accomplished. Meeting with Mr. Obama in the White House days before his inauguration, Mr. Bush urged him to preserve two classified programs, Olympic Games and the drone program in Pakistan. Mr. Obama took Mr. Bush’s advice….

But the good luck did not last. In the summer of 2010, shortly after a new variant of the worm had been sent into Natanz, it became clear that the worm, which was never supposed to leave the Natanz machines, had broken free, like a zoo animal that found the keys to the cage. It fell to Mr. Panetta and two other crucial players in Olympic Games — General Cartwright, the vice chairman of the Joint Chiefs of Staff, and Michael J. Morell, the deputy director of the C.I.A. — to break the news to Mr. Obama and Mr. Biden.

“I don’t think we have enough information,” Mr. Obama told the group that day, according to the officials. But in the meantime, he ordered that the cyberattacks continue. They were his best hope of disrupting the Iranian nuclear program unless economic sanctions began to bite harder and reduced Iran’s oil revenues.

American cyberattacks are not limited to Iran, but the focus of attention, as one administration official put it, “has been overwhelmingly on one country.” There is no reason to believe that will remain the case for long. Some officials question why the same techniques have not been used more aggressively against North Korea. Others see chances to disrupt Chinese military plans, forces in Syria on the way to suppress the uprising there, and Qaeda operations around the world. “We’ve considered a lot more attacks than we have gone ahead with,” one former intelligence official said….

Mr. Obama has repeatedly told his aides that there are risks to using — and particularly to overusing — the weapon. In fact, no country’s infrastructure is more dependent on computer systems, and thus more vulnerable to attack, than that of the United States. It is only a matter of time, most experts believe, before it becomes the target of the same kind of weapon that the Americans have used, secretly, against Iran.

DAVID E. SANGER,Obama Order Sped Up Wave of Cyberattacks Against Iran, New York Times, June 1, 2012