In 2012, multiple talks between Iran and the P5+1 - Britain, China, France, Russia, the United States and Germany - over Teheran's nuclear program were held, but they failed to bear fruit and the US and other Western countries enhanced the intensity and scope of sanctions against Iran.

However, the US also acknowledged that, so far, "Iran is not yet committed to building a nuclear arsenal, only to creating the industrial and scientific capacity to allow one if its leaders to decide to take that final step."

Defense secretary Leon Panetta said on CBS's Face the Nation last year that Iran is laying the groundwork for making nuclear weapons someday, but is not yet building a bomb and called for continued diplomatic and economic pressure to persuade Teheran not to take that step. Therefore, all the sanctions have been imposed out of fear that Iran will take that final step and build a nuclear arsenal.