Why does European aid to Ukraine vary? A nested analysis of domestic and international drivers
Journal: European Security
Year: 2026

What explains variation in burden-sharing during international conflicts? We analyse the crucial case study of the full-scale Russian invasion of Ukraine since 2022 to test military burdensharing theories, exploring both domestic and international factors. Data show significant and counter-intuitive variation between countries. We employ a nested research design that combines a cross-national quantitative analysis of 35 countries' military contributions to Ukraine between 2022 and 2024 with a qu