Assertiveness and war fatigue: European party dynamics during Russia’s war in Ukraine

Russia’s full-scale invasion of Ukraine in 2022 marked a watershed in European politics, compelling parties to adopt explicit positions on relations with Russia. Prior to the invasion, particularly parties on the ideological fringes often relied on strategic ambiguity. The 2022 attack triggered a surge in assertiveness toward Russia across much of the political spectrum, with only limited exceptions. This article examines whether these positions have endured or whether war fatigue among European political parties has led to declining assertiveness as the conflict has evolved. Drawing on roll-call votes in the European Parliament on key resolutions related to Russia and Ukraine between 2019 and 2025, we develop the Assertiveness Toward Russia Index (ATRI). The results show that mainstream parties have largely sustained their critical stance, while the European far right has become increasingly divided since 2022. The findings reconceptualise party group cohesion as dynamic yet durable, extending beyond short-lived rally effects.