But Iran also had a limited supply of centrifuges and materials to make new ones. With sanctions tighter than ever before, replacing damaged centrifuges now would become more challenging. In 2008, the IAEA estimated that Iran had enough components and materials on hand to build 10,000 centrifuges.9 If Stuxnet destroyed 1,000 of these, this cut the stockpile of centrifuges by 10 percent. On top of this, Iran lost about 10 percent of centrifuges each year to normal wear and tear. At that rate of attrition, “after five years, these guys are cooked,” says the IAEA’s Olli Heinonen.10
