This volume presents findings from a series of RAND reports examining the Russia-Ukraine War's geopolitical and military consequences and identifies cross-cutting implications for U.S. policymakers. In the series of reports and in the present volume, the authors employed a threefold approach. First, they surveyed historical wars of similar size, duration, and scope to bound expectations for the Russia-Ukraine War's likely effects and aftermath. Second, they identified diplomatic, military, economic, and normative changes that have occurred as a result of the war using government documents and senior leader statements; discussions with subject-matter experts; and prior open-source research. Third, because the war is ongoing, they highlighted plausible future events or changes that could alter states' responses to the conflict and, in turn, affect the report's preliminary findings.