Beyond the "Mother of All Agreements": Europe's Search for Strategic Autonomy in a Changing Security Order

For decades, Europe’s security has rested on what might be called the ‘mother of all agreements’: the transatlantic security architecture led by NATO and underwritten, in decisive terms, by the United States. That framework delivered deterrence, stability, and strategic continuity across the continent. Yet the current security environment has exposed the structural limits of a model in which Europe remains dependent on an external actor for core military capabilities. The European Commission’s White Paper for European Defence – Readiness 2030 frames the present context as one of acute and growing threat, while the European Council has stressed that Europe must assume greater responsibility for its own defence and become better equipped to act with greater autonomy (European Commission, 2025a; European Council, 2025).

Russia’s war against Ukraine, the erosion of the post-Cold War security order, and uncertainty over the long-term distribution of US strategic attention have revived the debate on European strategic autonomy. However, the concept remains both politically and analytically contested. The core difficulty lies not in recognising the need for stronger European defence capabilities, but in defining what autonomy should mean in practice and how far it can be pursued without undermining alliance cohesion. For the purposes of this paper, strategic autonomy is understood not as full strategic independence from the United States, but as Europe’s capacity to generate, coordinate, and sustain key military capabilities with sufficient political and operational reliability to assume a greater share of collective defence responsibilities. Treated as an open-ended aspiration, strategic autonomy risks becoming conceptually ambiguous and politically divisive; treated instead as a framework for strengthening Europe’s capacity to assume greater responsibility within the existing security architecture, it becomes more coherent and more actionable, particularly given the extent to which recent scholarship has already exposed its doctrinal and political ambiguity (Michaels and Sus, 2024).

Any serious response must begin with Europe’s actual capability gap. The central weakness is not merely political dependence, but operational dependence. Recent EU defence planning identifies several underdeveloped priority areas, particularly air and missile defence, military mobility, and strategic enablers such as intelligence and surveillance (European Commission, 2025a). At the same time, defence expenditure across the Union has increased substantially, with the European Defence Agency documenting both a significant upward trend in aggregate spending and the continued insufficiency of coordination, interoperability, and collaborative procurement across Member States (European Defence Agency, 2025). Europe is therefore spending more, but not yet spending in a sufficiently integrated manner to close its most consequential vulnerabilities.

Under these conditions, any rapid move toward full military autonomy remains constrained by two structural factors: enduring capability shortfalls and persistent strategic divergence among European states. The central policy question is therefore not whether dependency should be reduced, but under what strategic and institutional conditions this can be done credibly. A viable policy objective cannot be strategic separation from the United States in the short term, given the scale of Europe’s military limitations and the continuing embeddedness of American support in the continent’s security architecture (Meijer and Brooks, 2021). The more realistic objective is to reduce the most dangerous asymmetries within the alliance while laying the foundations for greater European responsibility over time.

The political dimension is equally decisive. For several member states, especially on NATO’s eastern flank, the American guarantee is not simply one component of European security; it remains its ultimate foundation. In that context, any autonomy agenda that appears to duplicate NATO structures or weaken the transatlantic link is likely to be interpreted as strategically irresponsible. A more sustainable approach is therefore to conceive European capability development as a way of reinforcing the alliance from within, rather than as an alternative to it. This makes the idea of a stronger European pillar inside NATO more realistic and politically viable than any maximalist vision of autonomy detached from the Atlantic framework (Ringsmose and Webber, 2020).

Critics may nonetheless argue that even a limited autonomy agenda risks duplicating NATO functions, fragmenting defence planning, and sending politically destabilising signals to those states that continue to regard the US guarantee as indispensable. This objection is strategically serious and cannot be dismissed rhetorically. However, a narrowly defined, capability-first approach focused on common procurement and enabling assets does not seek to substitute NATO’s command structure or collective defence role. Rather, it seeks to reduce the internal asymmetries that currently weaken the European contribution to the alliance itself. In that sense, the relevant distinction is not between autonomy and alliance, but between autonomy as decoupling and autonomy as a more credible form of burden-sharing.

The policy implication follows directly from this diagnosis. Europe does not face a binary choice between NATO and strategic autonomy. It faces a choice between remaining a structurally dependent security consumer or becoming a more capable and credible European pillar within the alliance. The immediate priority should therefore not be a diffuse agenda combining defence, energy, technology, and institutional reform all at once. Such breadth risks producing a conceptually attractive but operationally empty framework. A more effective strategy would be a sequenced, capability-first approach focused on those areas where dependence is both strategically costly and institutionally manageable.

Even so, implementation remains constrained by two persistent factors: the fragmentation of Europe’s defence industrial base and the enduring divergence of strategic cultures among Member States. These constraints do not invalidate a joint procurement agenda, but they do limit the speed and depth with which capability integration can be achieved. Any serious policy proposal must therefore be designed not for ideal conditions, but for a political environment in which consensus remains partial, industrial coordination remains uneven, and national procurement preferences continue to distort collective efficiency.

Against that background, the first concrete step should be for the European Commission to table, and for the Council to approve, a SAFE-backed joint procurement package under the Readiness 2030 framework, with implementation technically coordinated by the European Defence Agency. That package should be limited to a small number of critical capability areas where Europe’s dependence is most acute, namely intelligence and surveillance, military mobility, and integrated air and missile defence. This approach is institutionally grounded because SAFE already provides a financial and legal vehicle for common defence investment (Council of the European Union, 2025), while the Commission’s recent defence planning has already identified collaborative procurement and capability development in these sectors as urgent priorities (European Commission, 2025a).

This recommendation is preferable for three reasons. Politically, it is more viable than grand narratives of emancipation from the United States because it frames European capability development as burden-sharing rather than decoupling. Institutionally, it is feasible because it relies on instruments and actors that already exist within the EU framework. Strategically, it is sound because it targets the enabling capabilities that most clearly expose Europe’s current dependency structure. In this sense, strategic autonomy should be understood not as independence from allies, but as Europe’s capacity to assume greater responsibility within the security architecture on which it still depends, an interpretation that is both more realistic than claims of full autonomy (Meijer and Brooks, 2021) and more constructive than continued structural dependence within the alliance framework (Ringsmose and Webber, 2020).

Between 2025 and 2030, the EU should use SAFE and the broader Readiness 2030 agenda to reduce the capability asymmetries that most clearly expose Europe’s strategic dependence. The objective is not full independence from the United States, which is neither feasible nor necessary. It is to ensure that Europe can contribute more credibly to deterrence, sustain military readiness with greater resilience, and assume a larger share of collective defence without weakening transatlantic cohesion. Europe’s future security will not be secured by rhetorical invocations of autonomy, nor by indefinite reliance on an unequal transatlantic division of strategic labour. It will depend on whether the Union can convert the current defence readiness agenda into credible, coordinated capability development that strengthens both European responsibility and alliance cohesion (European Commission, 2025b).

References

Council of the European Union (2025) Council Regulation (EU) 2025/1106 of 27 May 2025 establishing the Security Action for Europe (SAFE) through the Reinforcement of the European Defence Industry Instrument. Brussels: Council of the European Union. 

European Commission (2025a) White Paper for European Defence – Readiness 2030. Brussels: European Commission. 

European Commission (2025b) SAFE | Security Action for Europe. Brussels: European Commission. 

European Council (2025) European Council conclusions on European defence, 6 March 2025. Brussels: European Council. 

European Defence Agency (2025) Defence Data 2024–2025. Brussels: European Defence Agency. 

Michaels, E. and Sus, M. (2024) ‘(Not) Coming of Age? Unpacking the European Union’s Quest for Strategic Autonomy in Security and Defence’, European Security, 33(3), pp. 383–405. 

Meijer, H. and Brooks, S.G. (2021) ‘Illusions of Autonomy: Why Europe Cannot Provide for Its Security if the United States Pulls Back’, International Security, 45(4), pp. 7–43. 

Ringsmose, J. and Webber, M. (2020) ‘Hedging Their Bets? The Case for a European Pillar in NATO’, Defence Studies, 20(4), pp. 295–317. 

European Commission and High Representative of the Union for Foreign Affairs and Security Policy (2025) Preserving Peace – Defence Readiness Roadmap 2030. Brussels: European Commission and High Representative of the Union for Foreign Affairs and Security Policy.