Long discounted by arms control critics, traditional nonproliferation efforts now are undergoing urgent review and reconsideration even by their supporters. Why? In large part, because the current crop of nonproliferation understandings are ill-suited to check the spread of emerging long-range missile, biological, and nuclear technologies. Attempts to develop a legally binding inspections protocol to the Biological Weapons Convention, for example, were recently rejected by U.S. officials as being inadequate to catch serious violators while being prone to set off false alarms against perfectly innocent actors. Missile defense and unmanned air vehicle (UAV) related technologies, meanwhile, are proliferating for a variety of perfectly defensive and peaceful civilian applications. This same know-how can be used to defeat U.S. and allied air and missile defenses in new ways that are far more stressful than the existing set of ballistic missile threats.