From fighting terrorists to stabilizing a war-torn country to waging all-out combat, military campaigns are increasingly shaped by networks that enable dispersed and disparate forces to collaborate by sharing data. Along with the high-precision sensors and weapons they connect, networks are turning information power into military power. Defense investment priorities are shifting from mechanized platforms and weapons to the information collectors, processors, links and services that compose these networks. With its unmatched defense resources and technological talents, the United States has pioneered networked warfare. But the United States will have company-not all of it friendly. For example, China and Al Qaeda, using very different doctrines, are showing interest in tapping the power of information. Indeed, Al Qaeda and its franchised affiliates are displaying cunning and resourcefulness in putting this power to work with virtually no investment. As adversaries exploit networks, the United States must seek new leverage by improving its fighters' ability to use information in war's confusing, critical, and violent conditions. Blessed with more, better, and timelier information, yet vexed by increasingly murky circumstances, the cognitive faculties of military decision makers-lieutenants no less than lieutenant generals-are more crucial than ever. In a forthcoming National Defense University book, the authors suggest why and how U.S. and allied forces should improve these faculties to attain new operational and strategic advantages, or at least to avoid the loss of the advantages they now enjoy. Although military combat is unique, the authors draw lessons from non-military sectors, including some in which urgent life-and-death decisions must be made. This paper summarizes their thinking. While this is neither the first nor the last word on why and how to gain cognitive advantage, it aims to take an integrated view, provide a geo-strategic context, broaden and heighten awareness, frame policy issues, offer preliminary advice, and indicate where research and analysis is needed.