This article examines the issues of social (re)integration in Ukraine, which were actualized during the Russian-Ukrainian war in 2014-2022. The first part of the article is devoted to the consideration of theoretical issues related to the conceptualization of social integration in the social sciences and the role of the state in reproducing social relations. The author assumes that during the last decades, ideas about the role of the state in these processes have changed significantly, which was caused by the departure (...) of the governments of developed democratic countries from the policy of the welfare state. This caused a reorientation of the state towards policies of inclusion, that is, targeted support and assistance to the most vulnerable social strata. The second part of the article is devoted to the consideration of the processes of social integration of migrants and refugees during the war in Ukraine. The author concludes that during the first full-scale invasion, processes of rethinking one's own national identity intensified in Ukrainian society. The armed confrontation and the catastrophic consequences caused by it contributed to the nationwide consolidation of Ukrainians and neutralized socio-cultural differences, which for a long time became the cause of political opposition and electoral divisions. Instead, the long stay of part of the territory and citizens of Ukraine under occupation under conditions of repressive and propaganda pressure, violent mobilization to the armed forces of the self-proclaimed republics and participation in the armed confrontation on the side of the occupiers revealed new divisions between Ukrainians who were on different sides of the front line. These divisions will obviously become an obstacle to the successful reintegration of Ukrainians after de-occupation, which will require a balanced and careful integration policy from the state authorities during the post-war reconstruction. (shrink)