Although the United States will continue to utilize overseas military bases in the next decade, the acquisition and improvement of long-range missiles by several potential aggressors will pose new operational and strategic problems for U.S. forces. Several states will likely attain a credible capability to threaten U.S. bases within their respective regions, despite the sophistication of U.S. missile defenses. Strategically, there are uncertainties about whether the United States can deter some of these new missile-capable actors. Deterrence problems will create new risks to U.S. deployed forces: if deterrence fails, U.S. troops will be at a higher level of exposure. Alternately, missiles will grant states some leverage to dissaude the United States from actually using overseas forces, as well as a means to coerce host states into denying access to the United States. Though several factors will mitigate these concerns, the question remains: How reliable will alliance-derived "tripwires" and other deployments be in the overall U.S. strategy of engagement? Alterations in force structure, tailored to these threats, will likely be needed.