By Andrea Shalal-Esa
WASHINGTON (Reuters) - The United States under former President George W. Bush began building a complex cyber-weapon to try to prevent Tehran from completing suspected nuclear weapons work without resorting to risky military strikes against Iranian facilities, current and former U.S. officials familiar with the program said.
Barack Obama accelerated the efforts after succeeding Bush in 2009, according to the sources who spoke on condition of anonymity because of the classified nature of the effort. The weapon, called Stuxnet, was eventually used against Iran's main uranium enrichment facilities.
The effort was intended to bridge the time of uncertainty between U.S. administrations after the 2008 presidential election in which Obama was elected, and allow more time for sanctions and diplomacy to avert Iranian nuclear weapon development, according to the current and former officials.
The sources gave rare insight into the U.S. development of its cyber-warfare capabilities and the intent behind it.
One source familiar with the Bush administration's initial work on Stuxnet said it had stalled Iran's nuclear program by about five years.
"It bought us time. First, it was to get across from one administration to the next without having the issue blow up. And then it was to give Obama a little more time to come up with alternatives, through the sanctions, et cetera," said the source.
Only in recent months have U.S. officials become more open about the work of the United States and Israel on Stuxnet, the sophisticated cyber-weapon directed against Iran's Natanz nuclear enrichment facility that was first detected in 2010.
The cyber-attacks provided the United States with an avenue to try to stop Iran from producing a suspected weapon without turning to military strikes against Iranian facilities - all at a time when U.S. forces already were fighting wars in Iraq and Afghanistan, the sources said.
In the end, senior U.S. officials agreed the benefit of stalling Iran's nuclear program was greater than the risks of the virus being harnessed by other countries or terrorist groups to attack U.S. facilities, one source said.
HUNDREDS OF MILLIONS OF DOLLARS
Two sources with direct knowledge of the U.S. program said it cost hundreds of millions of dollars to carry out.
The United States for years has been developing - and using - offensive cyber-capabilities to interfere with the computers of adversaries, including during the Battle of Falluja in Iraq in 2004 and in finding Osama bin Laden and other al Qaeda figures, the sources said.
Last year, the United States also explicitly stated for the first time that it reserved the right to retaliate with military force against a cyber-attack.
The New York Times reported on Friday that from his first months in office, Obama secretly ordered attacks of growing sophistication on the computer systems running the main Iranian nuclear enrichment facilities, greatly widening the first sustained U.S. use of cyber-weapons. The Times said the attacks were code-named Olympic Games.
White House spokesman Josh Earnest declined comment on the substance of the New York Times article, but denied "in the strongest possible terms" that it was an authorized leak of classified information. Obama is seeking re-election on November 6 in part on the strength of his foreign policy achievements.
Reuters reported on May 29 that the United Nations agency charged with helping member nations secure their national infrastructures plans to issue a sharp warning about the risk of the Flame computer virus that was recently discovered in Iran and other parts of the Middle East.
Stuxnet is one of many weapons in the U.S. cyber-arsenal, which some experts say also includes a data-gathering tool known as Duqu that was deployed to cull information about Iran's weapons programs.
Iranian officials have described the cyber-attacks as part of a "terrorist" campaign backed by Israel and the United States.
Some current and former U.S. officials, who asked not to be named, criticized the Obama administration for talking too freely to the media about classified operations.
Representative Peter King, the Republican chairman of the House of Representatives Committee on Homeland Security, said, "I believe that no one, including the White House, should be discussing cyber-attacks."
"The U.S. will now be blamed for any sophisticated, malicious software, even if it was the Chinese or just criminals," added Jason Healey, who has worked on cyber-security for the Air Force, White House and Goldman Sachs, and is now with the Atlantic Council research group.
(Additional reporting by Jim Finkle in Boston and Mark Hosenball in Washington; Editing by Warren Strobel and Will Dunham)
<em>In this Saturday, Nov. 12, 2011 photo, Iranian women and a man weave carpet in a workshop in Qom, 78 miles (125 kilometers) south of the capital Tehran, Iran. (AP Photo/Vahid Salemi)</em><br><br> Initial sanctions were imposed after Iranian students stormed the U.S. embassy and took diplomats hostage in 1979. Iranian products cannot be imported into the United States apart from small gifts, information material, food and some carpets.
<em>Former President Bill Clinton addresses the audience during the opening night dinner of the World Summit of Nobel Peace Laureates at the Field Museum Monday, April 23, 2012, in Chicago. (AP Photo/Charles Rex Arbogast)</em><br><br> In 1995, President Bill Clinton issued executive orders preventing U.S. companies from investing in Iranian oil and gas and trading with Iran. The same year, Congress passed a law imposing sanctions on foreign companies investing more than $20 million a year in Iran's energy sector.
<em>In this Thursday, Oct. 30, 2008 file photo, an Iranian money changer holds currency with Ayatollah Ruhollah Khomeini's image in Tehran, Iran. (AP Photo/Hasan Sarbakhshian, File)</em><br><br> In October 2007, Washington imposed sanctions on three Iranian banks and branded the Islamic Revolutionary Guards Corps a proliferater of weapons of mass destruction. The Treasury has since added numerous other Iranian banks to its blacklist. The Treasury has identified about 20 petroleum and petrochemical companies as being under Iranian government control, an action that put them off-limits to U.S. businesses under the trade embargo.
<em>This photo shows a branch of Iranian Bank Tejarat in Tehran on January 24, 2012 upon which the US Treasury announced sanctions claiming all of the Islamic Republic's major state-owned banks have now been subjected to punitive measures. (ATTA KENARE/AFP/Getty Images)</em><br><br> Congress approved tough new unilateral sanctions on June 24, 2010, aimed at squeezing Iran's energy and banking sectors. The new law imposed penalties on companies that supply Iran with refined petroleum products worth more than $5 million a year. It also effectively deprived foreign banks of access to the U.S. financial system if they did business with Iranian banks or the Revolutionary Guards.
<em>Oil workers gather by an oil well operated by Venezuela's state-owned oil company PDVSA in Morichal, Venezuela, on July 28, 2011. (RAMON SAHMKOW/AFP/Getty Images)</em><br><br> In May 2011, the United States announced new sanctions on Venezuela's state oil company, PDVSA, and six other smaller oil and shipping firms for trading with Iran in violation of the U.S. ban, prompting fury from Hugo Chavez's government.
<em>Members of Iran's paramilitary Basij militia parade in front of the former US embassy in Tehran on November 25, 2011 to mark the national Basij week. (ATTA KENARE/AFP/Getty Images)</em><br><br> On June 11, it announced new sanctions on the Revolutionary Guards, the Basij Resistance Force, and Iran's law enforcement forces. The sanctions froze any of the targets' assets under U.S. jurisdiction and barred U.S. persons and institutions from dealing with them.
<em>Secretary of State Hillary Clinton and Treasury Secretary Timothy Geithner (L) announce new sanctions against Iran at the State Department on November 21, 2011 in Washington, DC. (Photo by Mark Wilson/Getty Images)</em><br><br> On Nov. 21 the United States named Iran as an area of "primary money-laundering concern", a step designed to dissuade non-U.S. banks from dealing with it. The United States also blacklisted 11 entities suspected of aiding its nuclear programmes and expanded sanctions to target companies that aid its oil and petrochemical industries.
<em>US President Barack Obama (C) greets guests after speaking on nuclear security, touching on subjects from terrorism to Iran and North Korea, during a visit to Hankuk University of Foreign Studies in Seoul on March 26, 2012. (SAUL LOEB/AFP/Getty Images)</em><br><br> On Dec. 31, 2011, President Barack Obama signed into law a defense funding bill that imposed sanctions on financial institutions dealing with Iran's central bank, which is the main conduit for oil revenues. Sanctioned institutions would be frozen out of the U.S. financial markets.
<em>Hostesses stand in front of the construction site of the Saudi Basic Industries Corp. (SABIC) Technology Centre and Greater China Headquarters in Shanghai, China Friday, April 6, 2012. (AP Photo/Eugene Hoshiko)</em><br><br> On Jan. 13, 2012 the United States extended sanctions to Chinese state-run energy trader Zhuhai Zhenrong Corp, which it said was Iran's largest supplier of refined petroleum products. It also imposed sanctions on Singapore's Kuo Oil Pte Ltd and United Arab Emirates-based FAL Oil Company Ltd.
<em>Members of Iranian Revolutionary Guards attend a ceremony at the mausoleum of the late revolutionary founder Ayatollah Khomeini, commemorating 33rd anniversary of his return from exile after 14 years, and the 1979 Islamic Revolution which toppled pro-US Shah Mohammad Reza Pahlavi, just outside Tehran, Iran, Wednesday, Feb. 1, 2012. (AP Photo/Vahid Salemi)</em><br><br> The United States exempted Japan and 10 European Union nations from financial sanctions on March 20 because they had significantly cut purchases of Iranian oil, but Iran's top customers China and India remain at risk of such steps. On March 28 the Treasury set additional sanctions against Iranian engineering firms with ties to the Revolutionary Guards, as well as individuals and shipping companies with ties to the Islamic Republic of Iran Shipping Lines (IRISL).
<em>In this Sept. 27, 2000 file photo, an Iranian oil worker repairs a pipe at an oil refinery in Tehran. (AP Photo/Vahid Salemi, File)</em><br><br> On May 21 the Senate approved the latest tightening of sanctions on Iran's oil trade.
<em>In this Jan. 19, 2012 file photo, fishing boats are seen in front of oil tankers on the Persian Gulf waters, south of the Strait of Hormuz, offshore the town of Ras Al Khaimah in United Arab Emirates. (AP Photo/Kamran Jebreili)</em><br><br> On Aug. 12, 2010 the EU banned the creation of joint ventures with enterprises in Iran engaged in the oil and natural gas industries. Member states must prohibit the provision of insurance and re-insurance to the government of Iran. The import and export of arms and equipment that could contribute to uranium enrichment, or have a "dual use", is banned. The sanctions forbid the sale, supply or transfer of energy equipment and technology used by Iran for exploration and production or for refining or liquefying natural gas. The EU expects the effects of the sanctions to increase over time as existing parts wear out.
<em>EU foreign policy chief Catherine Ashton speaks during a media conference after a meeting of EU foreign ministers at the EU Council building in Brussels on Monday, Jan. 23, 2012. (AP Photo/Virginia Mayo)</em><br><br> In May 2011, EU foreign ministers added 100 new entities to a list of companies and people affected, including those owned or controlled by IRISL. Last October, the EU imposed sanctions on 29 people, extending the list targeting individuals associated with human rights violations to 61. On Dec. 1, the EU added 180 Iranians and entities to a sanctions blacklist that imposes asset freezes and travel bans on those involved in the nuclear program.
<em>In this March 13, 2008 file photo, gold coins and bars are shown at California Numismatic Investments in Inglewood, Calif. (AP Photo/Nick Ut, File)</em><br><br> On Jan. 23, 2012 the EU placed an immediate ban on all new contracts to import, purchase or transport Iranian crude oil and petroleum products. EU countries with existing contracts to buy oil and petroleum products were allowed to honor them until July 1. The EU also agreed to freeze the assets of Iran's central bank and ban trade in gold and other precious metals with the bank and state bodies.
<em>British Ambassador to the UN Mark Lyall Grant (C) speaks during a vote on broader military and financial sanctions on Iran over its suspect nuclear program during a UN Security Council at the UN headquarters June 9, 2010 in New York. (EMMANUEL DUNAND/AFP/Getty Images)</em><br><br> The Security Council has imposed four sets of sanctions on Iran, in December 2006, March 2007, March 2008 and June 2010. The first covered sensitive nuclear materials and froze the assets of Iranian individuals and companies linked with the nuclear program.
<em>A military truck carries a Sejil rocket as it is paraded during the annual Army Day military parade in Tehran on April 17, 2012. (ATTA KENARE/AFP/Getty Images)</em><br><br> The second included new arms and financial sanctions. It extended an asset freeze to 28 more groups, companies and individuals engaged in or supporting sensitive nuclear work or the development of ballistic missiles.
<em>Iranian President Mahmoud Ahmadinejad adjusts his goggles as he tours an exhibition on laser technology in Tehran on February 7, 2010. (ATTA KENARE/AFP/Getty Images)</em><br><br> The third, in 2008, increased travel and financial curbs on individuals and companies. It expanded a partial ban on trade in items with both civilian and military uses to cover sales of all such technology to Iran.
<em>A street money exchanger, puts US dollars in a plastic bag, in Ferdowsi St. in downtown Tehran, Iran, Wednesday, Dec. 21, 2011. (AP Photo/Vahid Salemi)</em><br><br> A Security Council resolution passed on June 9, 2010, called for measures against new Iranian banks abroad if a connection to the nuclear or missile programmes was suspected.
<em>Soldiers of the Iranian Revolutionary Guard walk past a satirical drawing of Statue of Liberty on the wall of the former US Embassy in Tehran, Iran, Friday, Nov. 25, 2011. (AP Photo/Vahid Salemi)</em><br><br> It expanded a U.N. arms embargo against Tehran and blacklisted three firms controlled by IRISL and 15 belonging to the Revolutionary Guards. The resolution called for the setting up of a cargo inspection regime.