Constraining the mobility of terrorists is one of the most effective weapons in the War on Terror. Limiting their movements markedly diminishes terrorists' ability to attack the United States, our interests abroad, or our allies. As both the 9/11 Commission noted in its main report and the 9/11 Commission staff noted in its separate monograph on terrorist travel, constraining the mobility of terrorists should be a key focus of the US Government's counterterrorism initiatives over the coming years. In light of the Commission's findings, Congress required the National Counterterrorism Center...