Claims to legitimacy count: Why sanctions fail to instigate democratisation in authoritarian regimes

International sanctions are one of the most commonly used tools to instigate democratisation in the post‐Cold War era. However, despite long‐term sanction pressure by the European Union, the United States and/or the United Nations, non‐democratic rule has proven to be extremely persistent. Which domestic and international factors account for the regimes' ability to resist external pressure? Based on a new global dataset on sanctions from 1990 to 2011, the results of a fuzzy set qualitative comparative analysis (fsQCA) provide new insights for the research on sanctions and on authoritarian regimes. Most significantly, sanctions strengthen authoritarian rule if the regime manages to incorporate their existence into its legitimation strategy. Such an unintended ‘rally‐round‐the‐flag’ effect occurs where sanctions are imposed on regimes that possess strong claims to legitimacy and have only limited economic and societal linkages to the sender of sanctions.