In the years between 2000 and 2022, thick security weakened and left European nationstates vulnerable to political, economic, and cultural ruptures with no organizational fallback in sight. A ‘post-security’ polity emerged that lacked the institutions that guarded security in the past. Post-security implies the absence of security mechanisms, not the absence of a need for security. The post-security polity privileges markets and peoples that cross borders, fosters austerity that threatens solidarity, and supports multicultural inclusion at the expense of nationalist exclusion. Security encapsulates what others have analyzed in terms of trust and risk. Explaining the ascendance of the nationalist right in terms of a security crisis is a more robust way of thinking of current events than explanations that focus on conceptions of cultural identity or purely economistic explanations. In contrast to the past where security issues were national, contemporary security issues such as climate change, disease, migration, terrorism, and finance are transnational in scope. The globalization of security and its opposites – insecurity, threats, and fears – raise questions of responsibility and render contemporary security crises less tractable of solutions. Right nationalists have stepped into the void with simple solutions to difficult problems that require complex and transnational solutions.