Interoperability as a defining principle of Europe’s digital sovereignty agenda

Digital sovereignty has become one of the defining policy debates of the European decade. It sits at the intersection of geopolitics, industrial policy, cybersecurity, and constitutional values. Yet despite its prominence, the term remains contested. For some, sovereignty means control over infrastructure and data — preferably within national or European borders. For others, it means the ability to act independently in a world of technological interdependence. The distinction is not semantic. It shapes how Europe regulates platforms, designs cloud policy, and positions itself between the United States and China.

Cloud computing lies at the heart of this debate. The global market is heavily concentrated in the hands of a few hyperscalers and their dominance is not merely commercial; it is infrastructural. They provide the backbone for public administrations, hospitals, financial institutions, universities, and increasingly for artificial intelligence systems. Their vertically integrated ecosystems — compute, storage, identity, AI tooling, proprietary databases — generate immense efficiencies. They also create structural dependencies. Once deeply embedded in one environment, switching becomes technically complex and economically costly. Vendor lock-in remains a central feature of the cloud economy.

The European Union’s response to this concentration has taken multiple forms. Through legislative initiatives such as the Data Governance Act and the Data Act, and through cybersecurity certification schemes, the European Commission has attempted to strengthen data portability, clarify governance rules, and reduce asymmetries of power. At the same time, the ambition of “technological sovereignty” has inspired industrial initiatives such as GAIA-X — an attempt to create a federated, European-aligned cloud ecosystem grounded in shared standards and values.

Yet GAIA-X illustrates both the necessity and the difficulty of sovereignty projects rooted in infrastructure-building alone. Launched with considerable political symbolism, it promised a European alternative to hyperscaler dominance. Over time, however, it struggled with governance complexity, diverging member interests, unclear market incentives, and the paradox of including the very non-European providers it initially sought to counterbalance. The initiative did not fail for lack of ambition; it faltered because constructing parallel infrastructure in a highly capital-intensive and globally integrated market proved extraordinarily difficult. Sovereignty by replication — building European “equivalents” to American or Chinese platforms — encountered structural limits.

At the same time, pure market concentration remains deeply problematic. Network effects, economies of scale, and the gravitational pull of proprietary ecosystems risk entrenching a small number of providers as systemic gatekeepers. This concentration raises competition concerns, but also constitutional ones. When digital infrastructure becomes indispensable for public administration, the dependency of democratic institutions on a handful of foreign-headquartered corporations acquires geopolitical significance. The debate is therefore not reducible to antitrust policy; it concerns the architecture of democratic self-government in a digital age.

Between enclosure and resignation lies a third path: interoperability.

Interoperability reframes sovereignty not as isolation or duplication, but as capacity within interdependence. It emphasizes the ability to move, to connect, to federate, and to exit. In practical terms, interoperability means shared protocols, open standards, portability requirements, and interconnection mechanisms that lower switching costs and prevent structural lock-in. It transforms sovereignty from a static notion of territorial control into a dynamic ability to reconfigure dependencies.

There are strong historical precedents for this logic. Consider the standardized shipping container. Before containerization, global trade was slow, fragmented, and vulnerable to theft and delay. The breakthrough was not a new empire or a supranational port authority, but a shared technical specification. Once container dimensions were standardized through international agreement, any compliant ship, crane, truck, or railway could interoperate with any other. Trade volumes expanded dramatically. Yet no state surrendered customs authority, maritime jurisdiction, or regulatory power. Sovereignty did not shrink; it became more operational because infrastructure could connect across borders without political merger.

Or take something as seemingly mundane as measurement. Before the spread of the metric system, Europe was a patchwork of local units — feet, ells, stones, and cubits that varied by region. Industrial scaling across borders was nearly impossible. The adoption of the metric system did not abolish national governments. It did not dissolve borders. It created a shared language of quantification. Engineering, science, and trade flourished precisely because sovereign states agreed on interoperable standards while retaining full political independence. Measurement became infrastructure for autonomy, not its negation.

The same pattern appears in identity systems. After the First World War, chaotic and inconsistent travel documentation hampered cross-border mobility. Through League of Nations negotiations, passport formats and visa practices were standardized. States retained complete discretion over who could enter their territory. But interoperable documents allowed those sovereign decisions to be recognized and processed by others. Borders did not disappear; they became administratively manageable at scale.

Even scientific knowledge offers a parallel. Before the eighteenth century, plants and animals were described differently across languages and empires. The Linnaean system of binomial nomenclature created a universal taxonomy. A species identified in Sweden could be discussed in Spain or Brazil under the same classification. No global government enforced this order. Yet by standardizing naming conventions, sovereign states and scientific institutions could coordinate research and exchange findings across continents. Shared standards amplified intellectual capacity without centralising political authority.

One could extend the analogy further. The Gregorian calendar gradually replaced a patchwork of incompatible dating systems across Europe and beyond. States adopted a common temporal framework for civil purposes while maintaining religious and political autonomy. Commerce, diplomacy, and navigation benefited from synchronized timekeeping. Again, sovereignty persisted — but it functioned within a shared temporal infrastructure.

Across these examples — shipping containers, measurement systems, passports, taxonomies, calendars,— a consistent lesson emerges. Interoperability does not dissolve sovereignty. It enables it to operate within networks. Shared standards reduce friction, lower coordination costs, and create exit options without requiring political unification.

The same principle applies to digital infrastructure. When cloud systems are sealed silos, sovereignty becomes fragile: dependency hardens, mobility declines, and strategic options narrow. But when systems are designed to interoperate — through shared protocols, portability standards, and governed interconnection — sovereign actors retain the ability to choose, to shift, and to coordinate. Just as containerization did not create a world state, and the metric system did not abolish national law, interoperable cloud architectures need not erase jurisdictional authority.

Historically, the most resilient political orders were not those that isolated themselves from networks, but those that shaped the standards under which networks operated. Interoperability has repeatedly functioned as a quiet but decisive instrument of sovereign capacity. In the digital age, it may once again prove to be the difference between dependency and democratic control.

The internet itself offers a more recent example. Its foundational protocols — TCP/IP, SMTP, HTTP — were designed as interoperable standards rather than proprietary enclosures. No single actor “owned” email or the web. This openness allowed innovation, competition, and global scaling while enabling states to regulate services built atop the network. The democratic potential of the internet was not guaranteed, but its interoperable architecture prevented early monopolisation at the protocol layer.

Cloud computing evolved differently. Hyperscalers built vertically integrated environments optimized for performance and security, but not for portability. The economic logic is understandable: differentiation and integration drive competitive advantage. Yet this architecture complicates sovereign choice. When data gravity, proprietary AI services, and bespoke integrations accumulate within one provider, exit becomes economically irrational even if legally permissible.

Recent technical developments suggest a subtle adjustment. When a provider such as Amazon Web Services introduces managed multicloud connectivity — beginning with interconnection to Google Cloud — it does not eliminate concentration. Nor does it dissolve lock-in. But it reduces friction in cross-cloud architectures. It makes distributing workloads across providers somewhat more feasible. Interoperability becomes part of the product offering rather than an adversarial afterthought.

This shift is modest but politically significant. It reflects pressure from enterprise customers, regulators, and public-sector procurement policies that increasingly demand resilience and optionality. In Europe, sovereignty debates have amplified this demand. Public institutions now ask not only where data resides, but how easily it can be moved. Exit options become a measure of autonomy.

The value of interoperability becomes clearer when contrasted with enclosure-based sovereignty models. Building national or regional “fortress clouds” may promise control, but it risks fragmentation, reduced economies of scale, and diminished innovation capacity. It can also entrench domestic monopolies. Democratic sovereignty requires more than jurisdictional boundaries; it requires pluralism, contestability, and resilience. Systems that cannot interoperate are brittle. They trap users as effectively as foreign platforms do.

At the same time, interoperability is not a panacea. Without governance, it can entrench dominant actors by allowing them to define standards. Without competition enforcement, portability rights may exist only on paper. Without cybersecurity coordination, interconnection can increase attack surfaces. Democratic interoperability therefore demands institutional scaffolding: certification schemes, enforceable data portability rights, competition oversight, and transparent standards-setting processes.

Here the European Union holds structural leverage. As a large regulatory market, it can condition access on interoperability requirements. It can mandate technical documentation, standardized APIs, and data export formats. It can align procurement rules with portability criteria. In doing so, it shifts the sovereignty debate from ownership to rules of engagement.

The critical question is not whether Europe should build its own hyperscalers — a goal that has thus far proven elusive — but whether it can shape the interoperability environment in which all providers operate. 
A democratic theory of digital sovereignty therefore rests on three pillars. First, concentration must be constrained through competition policy and transparency. Second, attempts at infrastructural replication must be assessed realistically, avoiding symbolic projects that lack economic viability — a lesson underscored by the struggles of GAIA-X. Third, and most importantly, interoperability must be treated as a constitutional principle of digital governance.

Historically, states became stronger not by isolating themselves from networks, but by shaping them. Railways, telegraphs, postal systems, financial clearinghouses — each required common standards to function across borders. Sovereignty survived because it was embedded in interoperable architectures governed by shared rules. The same logic applies to the cloud.

Digital sovereignty in a democratic context should not be defined by the thickness of digital walls, but by the credibility of exit options, the enforceability of standards, and the resilience of interconnected systems. Interoperability provides the technical foundation for these qualities. It lowers dependency without demanding isolation. It enables cooperation without surrendering regulation. It turns interdependence into governable structure.

Cloud markets remain concentrated, and hyperscalers retain immense structural power. European industrial initiatives have struggled to counterbalance that reality directly. Yet the path forward may not lie in constructing parallel fortresses, but in mandating bridges.Interoperability is not a concession to globalization; it is the mechanism through which democratic societies can shape it.