Over the summer of 2012, despite increased international pressure and economic sanctions, Iran doubled the number of nuclear centrifuges installed in its underground Fordow site, stopping just short of the capacity to produce nuclear fuel. President Obama has rejected Israeli Prime Minister Netanyahu's call to draw a "red line" that would trigger U.S. military action. What are the costs and benefits of military action? Can Israel live with a nuclear Iran, or is it time to launch a pre-emptive strike?