"I don't think we're talking about Iran building an atom bomb. It's about the regime being in a position to force concessions from the West through its potential to build an atom bomb", says nuclear physicist Behrooz Bayat. However, there's a fear that Israel will respond to this threat with violence. "They already have the knowledge to build their own nuclear bomb! Now is the time for decisions", says the director of Israeli military intelligence. The UN is committed to a policy of sanctions, but if Thursday's talks with Iran yield no results, will they have to think again?