Russian invasion as a European issue: Vertical Europeanisation of national political debates and the war in Ukraine

This article examines political discourse in the European Union (EU) in the aftermath of the full-scale Russian invasion of Ukraine. While prior studies have explored the policy and public opinion effects of this recent crisis, we complement them by investigating its potential to Europeanise national political debates across the EU. We hypothesise that the war, an external security threat, which was met with a unified response from the bloc and significant protagonism from EU leaders, became a ‘European issue’, triggering vertical Europeanisation of national political debates. We test this hypothesis through a novel big data approach: we analyse Facebook posts from political parties across all 27 EU member states from 2019 to early 2023. This dataset allows us to track mentions of European institutions and leaders in national political discourse for the whole of the EU. Our analysis reveals a significant increase in the vertical Europeanisation of domestic political debates in the year after the Russian invasion, strongly associated with discussions of the conflict. We also find that the increase in Europeanisation in the context of military threat is driven primarily by pro-European parties and occurs to a greater extent in countries with weaker institutions and those geographically more distant from Ukraine. These findings have significant implications for understanding how external security threats can prompt the Europeanisation of national political debates, offering new avenues for understanding the role of crises in shaping EU integration dynamics.