The 2013 class of Nuclear Scholars, selected from a very competitive applicant pool, contained some of the best and brightest young professionals in the nuclear field. Drawn from graduate programs, the national labs, the civil service, and the U.S. military, these Nuclear Scholars participated in six monthly workshops that focused on a wide range of nuclear topics. These topics included extended deterrence and assurance, stockpile stewardship, nuclear materials security, Iranian and North Korean proliferation, international nonproliferation norms and treaties, missile defense, and nuclear targeting. The program culminated in a final meeting at which the Nuclear Scholars presented their own research to a panel of senior experts. The papers resulting from these presentations are contained in this year’s volume.