Iran, Stuxnet and International Diplomacy

US and Israeli estimates of Iran's nuclear timetable are less alarming than they were just months ago. Hillary Rodham Clinton says that's due to international sanctions. The outgoing chief of Israeli intelligence cites what he calls "technical setbacks." The New York Times reports it's the result of Stuxnet, tested at Israel's Dimona nuclear complex with assistance from the United States. That computer virus reportedly caused Iranian centrifuges to spin out of control while convincing operators all was well. It's also capable of disrupting electrical power grids, air traffic control systems or military networks, including those of its own developers. How vulnerable is the US? What will Stuxnet mean for diplomacy, including upcoming talks about Iran's nuclear program?