In this photo from March 2009, an Israeli Air Force F-15I fighter jet lands at the Hazerim Air Force Base in the southern Israeli Negev desert during a media event. The Israeli aerial arsenal includes the F-16I, which military officials said was capable of reaching Iranian airspace without refueling. Jack Guez/AFP/Getty Images hide caption

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U.S. Secretary of State Hillary Clinton arrives at Don Muang Airport in Bangkok on July 21, ahead of a meeting of the Association of Southeast Asian Nations. During her visit, Clinton said a nuclear Iran could be contained by a U.S. "defense umbrella." Wason Wanichakorn/AP File hide caption

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Iranian hard-line students burn U.S. and British flags on June 23, 2009, during a protest outside the British Embassy in Tehran after the country's disputed presidential elections. The conservative incumbent, Mahmoud Ahmadinejad, was re-elected. AFP/Getty Images hide caption

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In this photo from April 2007, Iranian President Mahmoud Ahmadinejad delivers a speech during a visit to the Natanz uranium enrichment facility about 200 miles south of Tehran, the country's capital. During the speech, Ahmadinejad announced that Iran was producing enriched uranium on an industrial scale, warning that the Islamic republic would defend its nuclear rights "to the end." Atta Kenare/AFP/Getty Images hide caption

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Iranian President Mahmoud Ahmadinejad visits the Natanz uranium-enrichment facilities, about 200 miles south of Tehran, in April 2008. Ahmadinejad announced on Iranian state television during the visit that Iran has begun the installation of some 6,000 new centrifuges, adding to the 3,000 centrifuges already at the facility. The Office of the Presidency of the Islamic Republic of Iran via Getty Images hide caption

itoggle caption The Office of the Presidency of the Islamic Republic of Iran via Getty Images

Located about 200 miles south of Tehran, the nuclear facility at Natanz (shown here in 2005) has fed concerns that Iran is seeking to produce nuclear weapons. The International Atomic Energy Agency says Iran is enriching uranium at Natanz and as has already produced enough nuclear fuel for a single nuclear bomb, provided Iran develops the capability to enrich the material further to weapons grade. Henghameh Fahimi/AFP/Getty Images hide caption

itoggle caption Henghameh Fahimi/AFP/Getty Images

This Aug. 13, 2004, satellite image provided by DigitalGlobe and the Institute for Science and International Security shows the military complex at Parchin, Iran, about 19 miles southeast of Tehran. Anonymous/AP hide caption

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