leadership of President Ali Akbar Hashemi Rafsanjani and Supreme Leader Ali Hosseini Khamenei sought to revive Iran's overt nuclear civilian program and expand undeclared nuclear activities during the 1990s. According to a strategic dossier from International Institute for Strategic Studies, Iran turned away from Western suppliers and obtained nuclear assistance from Russia and China in a number of key areas, including uranium mining, milling and conversion, as well as technology for heavy-water research reactors. However, Washington intervened with Moscow and Beijing to prevent Iran from fully acquiring its list of nuclear power and fuel-cycle facilities. The 1990s also saw Iran expand its furtive nuclear research into conversion, enrichment and plutonium separation. "Most importantly, on the basis of additional centrifuge assistance from the A.Q. Khan network, Iran was able to begin the construction of pilot-scale and industrial-scale enrichment facilities at Natanz around 2000." Full exposure of Iran's nuclear activities came in 2002, when an Iranian exiled opposition group, the National Council of Resistance of Iran (NCRI) declared the Natanz project in August of that year. Since that time, international pressure on Iran has remained steady, hampering but not halting the country's nuclear development. Iran remains legally bound to the NPT and states its support for the treaty. There are various estimates of when Iran might be able to produce a nuclear weapon, should it choose to do so: A 2005 assessment by the International Institute for Strategic Studies concluded "if Iran threw caution to the wind, and sought a nuclear weapon capability as quickly as possible without regard for international reaction, it might be able to produce enough HEU for a single nuclear weapon by the end of this decade", assuming no technical problems. The report concludes, however, that it is unlikely that Iran would flatly ignore international reactions and develop nuclear weapons anyway. A 2005 US National Intelligence Estimate stated that Iran was ten years from making a nuclear weapon. In 2006 Ernst Uhrlau, the head of German intelligence service, said Tehran would not be able to produce enough material for a nuclear bomb before 2010 and would only be able to make it into a weapon by about 2015. A 2007 annual review the International Institute for Strategic Studies in London stated that "If and when Iran does have 3,000 centrifuges operating smoothly, the IISS estimates it would take an additional 9-11 months to produce 25 kg of highly