Abstract: In November 2013, a historic agreement on Iran’s nuclear program was reached between Iran and the world powers, raising the prospects for a long-term agreement that would end the Iran nuclear crisis and set the stage for normal relations between Iran and the West. This book seeks to provide readers with a comprehensive understanding of this agreement and the protracted process that preceded it. It examines in details the nuclear negotiations between Iran and the world powers, focusing on the origins and evolution of the Iran nuclear crisis, the unilateral and the multilateral sanctions. It also looks at the relationship between nuclear and various non-nuclear regional issues, as well as the long-term implications for the U.S.-Iran relations.