First dramatically, then with ever-growing complexity, World War I began a long-running, openly contentious reordering of gender relations, gender understandings, and public gender regimes. Mobilization for total war articulated men’s citizenship to soldiering; women’s to motherhood. Harnessed to family in multifarious ways, each profoundly altered and strengthened belonging in the nation. Those processes of regendering shaped interwar public policy across multiple spheres: welfare provision and social services; broader social policy and public health; regulation of sexuality and reproductive rights; education and public morality. While presenting across Europe as common exigencies and desiderata, in democratic polities no less than in fascist regimes or the Soviet Union, this welfarist political complex varied markedly with different types of polity. The “front experience” became processed by many younger veterans and aspiring soldiers into a militarized outlook of aggressively misogynist, heedlessly violent, and empathy-purged masculinity.