* Tehran secretly imported 1.8 tons of nuclear material from China in 1991 and processed some of it to manufacture uranium metal, which would be of no use in Iran's commercial program but would be integral to weapons production.
* As early as 1989, Pakistani generals offered to sell Iran nuclear weapons technology. Abdul Qadeer Khan, a Pakistani nuclear scientist regarded by the United States as a purveyor of nuclear secrets, has helped Iran for years. "Pakistan's role was bigger from the beginning than we thought," said a Middle Eastern intelligence official.
* North Korean military scientists recently were monitored entering Iranian nuclear facilities. They are assisting in the design of a nuclear warhead, according to people inside Iran and foreign intelligence officials. So many North Koreans are working on nuclear and missile projects in Iran that a resort on the Caspian coast is set aside for their exclusive use.
* Russian scientists, sometimes traveling to Iran under false identities and working without their government's approval, are helping to complete a special reactor that could produce weapons-grade plutonium. Moscow insists that it is providing only commercial technology for the civilian reactor under construction near the Persian Gulf port of Bushehr, an assertion disputed by Washington.
* In recent months, Iran has approached European companies to buy devices that can manipulate large volumes of radioactive material, technology to forge uranium metal and plutonium and switches that could trigger a nuclear weapon. European intelligence sources said Tehran's shopping list was a strong indication that Iran has moved to the late stages of weapons development.
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Regional Impact
A nuclear-armed Iran would present the United States with a difficult political and military equation. Iran would be the first avowed enemy of Israel to possess a nuclear bomb. It also has been labeled by the Bush administration as a state sponsor of international terrorism.
Iranian nuclear weapons could shift the balance of power in the region, where Washington is trying to establish pro-American governments in Afghanistan and Iraq. Both of those nations border Iran and are places where Tehran wants to exert influence that could conflict with U.S. intentions, particularly in Iraq.
