lobelog.com:

Iran began developing a nuclear program in the 1950s with American assistance, under President Dwight Eisenhower’s “Atoms for Peace” program. This was an effort to head off the possibility of nuclear proliferation by offering American research, infrastructure, and expertise to countries that were interested in developing nuclear programs for peaceful use. Iran signed the Non-Proliferation Treaty (NPT) in 1968, which obliges it not to pursue nuclear weapons. After Shah Muhammad Reza Pahlavi, an American ally, was removed from power by the 1979 Islamic Revolution, all cooperation between Iran and the United States on nuclear power was halted. Ayatollah Ruhollah Khomeini, who became Iran’s new leader after the revolution, showed little interest in the nuclear program, but it did continue. Today, Iran’s primary nuclear facilities include a civilian power plant at Bushehr, four medical reactors at Isfahan, a research reactor at Tehran, and uranium enrichment facilities at Natanz and Fordow. 

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