In this follow-on report to Europe's High-End Military Challenges: The Future of European Capabilities and Missions, the CSIS Europe, Russia, and Eurasia Program and International Security Program examine the other side of the coin of European military effectiveness: the political will of European countries to conduct military missions and operations. The report identifies the endogenous and exogenous factors constraining or increasing political will and maps them onto six country case studies. Four prototypes of political will emerged from the analysis: global partners, international activists, constrained partners, and minimalists. The report then assesses the political will of European allies and partners to conduct fifteen types of military missions and operations worldwide, from peacekeeping to large-scale combat. It concludes with a summary of key findings. First, it finds that internal and external factors—such as strategic culture and alliance dependence, respectively—will continue to constrain European political will in many cases, even after the Russian invasion of Ukraine. Second, European states are more likely to have the political will to engage in military missions at the lower end of the conflict spectrum (such as maritime patrol missions) and less likely at the higher ends of the spectrum, except in cases of significant collective or national defense.