The war initiated by the Russian Federation against Ukraine in 2022 can be seen as a drastic shock event with unpredictable long-term socio-political consequences at the national, regional and global levels. This study aims to identify the impact of war-related disturbances on the dynamics of social cleavages in Ukraine, in particular the possibility of deepening or diminishing such cleavages or promoting the occurrence of new ones. For decades, the internal partition of Ukraine into East and West has been attributed to national self-identification, linguistic and religious peculiarities and the geopolitical preferences of residents of different regions. Shortly before and after the outbreak of the Russian invasion, fundamental changes in Ukrainian society and domestic politics became evident, some of which can be interpreted as signs of the mitigation of social cleavages. Our findings revealed at least two significant shifts in these ‘old’, traditional cleavages: one occurred after the Revolution of Dignity and the annexation of Crimea by Russia in 2014, and the second one is emerging now, due to the full-scale war on Ukrainian territory against the Ukrainian people. More broadly, this research aims to assess the resilience of social cleavages in the face of a shock event.