Crises are important turning points in the process of regional integration. While threatening polities in the making with disintegration, they create opportunities for further political development (Schmitter 1970, Skowronek 1982). In this paper, we study boundary change (“bordering”), an important marker of polity formation in the Rokkanian tradition, in the crisis period of European integration. In response to a crisis, the EU has the option to change its internal or external boundaries or both. Moreover, it can change by increasing or decreasing boundary closure and boundary control. We assume that the specific direction of crisis-induced boundary change depends on the nature of the crisis.
Specifically, we build on the typological distinction between “failures” and “attacks” (Schimmelfennig 2024). Failures originate in unanticipated policy shocks that expose flaws in policy design and capacity deficits. By contrast, attacks result from political resistance against the polity’s identity, fundamental values, and constitutional principles. We hypothesize that, whereas the EU reacts to failures by increasing boundary control (i.e., allocating additional competencies and resources to the EU), the response to attacks is increasing boundary closure towards the attacker and opening boundaries towards the community's defenders. We distinguish between exogenous and endogenous crises changing the external and internal boundaries respectively. Finally, we distinguish between symmetrical and asymmetrical crises, with the expectation that the former are more likely to significantly change boundaries. To trace these changes, we use the EUROBORD Boundary Configuration dataset, tracking shifts in boundary closure and control across multiple crises and challenges that vary in nature.