In Space as a Warfighting Domain: Reshaping Policy to Execute 21st Century Spacepower, Dr. Lambakis has developed a handbook for senior policy makers, defense planners, and critical thinkers outside the U.S. government that presents the case that the United States is currently in a transition phase with respect to its national security space policy. The monograph lays the groundwork for reworking current space policy vision and goals, an essential step for improving missile defense, space control, and the overall military effectiveness of the U.S. armed forces. The U.S. dependence on space is growing, which means failure to respond smartly to a potential adversary’s aggressive military use of space could have deadly consequences. Possible answers to these threats, in the form of improved space control capabilities and the application of force in space, remain problematic because these missions have not been properly authorized and adequate money has not been appropriated to develop weapon systems. Even though reality dictates that space is now a warfighting arena, policy uncertainty about which U.S. military activities in space are permissible remains, which places the country in a dangerous situation. The national vision for space, and the country’s national security space policy, should fold in the reality of possible combat engagements in space. If we are to ensure space dominance, the U.S. administration and the nation’s lawmakers will have to take some policy risks in a time when near-peer competition in space is growing rapidly and significantly. He argues that it is time to lay a firm policy basis for the continued positive evolution of U.S. spacepower.