The U.S. Department of Defense has been increasingly focused on competition with Russia and China and, in the extreme, the possibility of great power war. To inform thinking about what might follow such a war, RAND researchers generated four hypothetical near-term great power war scenarios and assessed how the postwar strategic environment would change in each scenario. These scenarios offer planners and decisionmakers plausible narratives about future great power wars with different features to help them examine assumptions and think about how wartime choices could affect postwar U.S. objectives. The scenarios in this report illustrate the complex relationships between wartime and postwar goals. They show how a U.S. victory could provoke a stronger alignment between China and Russia or lead to greater determination and hostility in the recently defeated adversary. A U.S. defeat, meanwhile, could enhance U.S. efforts to recruit allies and partners, while also increasing the likelihood of nuclear proliferation among U.S. allies and partners. Indeterminate war outcomes could heighten the risk of a quick return to conflict while sapping alliance cohesion. The complexity and variability of these results highlight the importance for U.S. policymakers of considering postwar outcomes in prewar planning.