President Obama boasted today that he's isolated Iran more than ever before and imposed the toughest sanctions ever because of its nuclear program. But that's not all. Iran's nuclear software has been disrupted and nuclear scientists allegedly have been killed. Are these the covert precursors of open hostilities? Will such tactics make Iran take a harder line? Is that why it shot down an American unmanned drone and tried to kill a Saudi ambassador on US soil? What about tough talk from Israeli leaders? Will that make diplomacy harder still and make Iran more determined to develop a nuclear bomb?