Description
As the international order shifts and US–China rivalry intensifies, the European Union's pursuit of "digital sovereignty" is widely read as evidence of an increasingly powerful supranational actor — the "Brussels effect," the "geopolitical Commission." Yet the EU's flagship instruments for this goal, public-private partnerships in critical digital infrastructure, succeed in some sectors and stall in others. Who, then, actually drives European digital sovereignty? Applying Moravcsik's liberal intergovernmentalism through theory-guided process-tracing, this paper compares the two most similar partnerships: cloud (IPCEI-CIS) and 5G (SNS JU). It argues that member states' politico-economic interests, not EU institutions, are decisive. Where national interests converged against US hyperscalers, cooperation produced an effective, industrial-deployment partnership in the cloud; where they diverged — states torn between US security alliances and the Chinese market over Huawei — contestation left only a weaker, research-focused body in 5G. Digital sovereignty thus advances only within the limits of protected national interests, with the EU acting as facilitator rather than sovereign. Foregrounding cooperation and contestation amid rapid technological change, the paper repositions member states in a debate that has overstated supranational power.