Bibliogr. s. 821-823. This work was supported by the European Research Council [101045227].

External wedging poses a fundamental challenge to European strategic autonomy. Powerful external actors often exploit or create internal divisions within the European Union (EU), whether intentionally or not. Why can the EU successfully resist external wedging in some cases but not others? Drawing on the European integration literature, we contend that the EU’s ability to repel external wedging requires a critical mass of member states determined to bind the EU together and is facilitated by the degree of institutional centralisation. However, cohesion is a necessary but not sufficient condition for the EU to repel external wedging. Drawing on alliance scholarship, we argue that powerful and determined external dividers can often break EU cohesion. Assuming a high degree of internal cohesion, we posit that the greater the EU binder(s)’ reward/coercive power and stakes relative to the divider’s on a given issue, the higher the EU’s chances of repelling external wedging.