Tilly versus Milward: Experimental Evidence of Public Preferences for European Defense Amidst the Russian Threat.

Following the "bellicist" school of state formation, the external threat of war is expected to spur polity formation by centralizing military capacity (Tilly, in Coercion, Capital, and European States, Oxford, Basil Blackwell, 1990). It has been argued that Russia's invasion of Ukraine could provide such an impetus for centralization in the EU polity (Kelemen & McNamara, Comparative Political Studies, 55(6):18-34, 2022). We adapt the Tillian argument to the era of mass democracy, where governments need citizen support. Public support is crucial because it can constrain governments in times of crisis, especially regarding salient policies. We do not yet understand what degree of centralization the European public supports and under which conditions it can increase. We conduct an experiment where we vary both the Russian (escalation from presence in Ukraine to the invasion of Moldova or Lithuania) and the American responses (continuation of support vs. withdrawal) and see how European preferences vary for polity building in defense. We field our experiment in 7 countries (Germany, France, Italy, Portugal, Finland, Poland, and Hungary) with different sensitivities and exposures to the war in Ukraine. We propose an alternative argument to the Tillian approach based on the seminal Milwardian argument according to which polity coordination of national capacities is preferred (Milward, in The European Rescue of the Nation State, University of California Press, Berkeley and Los Angeles, 1992). We show theoretically and empirically that external threats can actually hamper polity centralization, at least in the short term. Rather, they strengthen the subunits of a polity through coordination.