While the term ‘‘weapons of mass destruction’’ (WMD) is a relatively new one, the effort to stop the spread of arms and weapons systems that can inflict mass harm is by no means new. Indeed, efforts to stop the production and possible use of these most fatal weapons have been successful by many accounts. From agreements following World War I to ban mustard gas to the establishment of the International Atomic Energy Agency to the nearly universal acceptance of the Nuclear Nonproliferation Treaty to the inauguration of the Chemical Weapons Convention in 1997, the international community has made great strides in limiting states’ ability to pursue, and interest in pursuing, WMD. Libya’s recent decision to dismantle and allow international inspections of its own WMD program serves as evidence of the effectiveness of today’s nonproliferation regime.