Europe’s Defense Dilemma | Council on Foreign Relations

Political decision-making among Europeans in case of a crisis would need to be reformed to work as efficiently as the North Atlantic Council in NATO. Although Article 42(7) itself can be invoked unilaterally, many EU instruments that would support a military response remain subject to unanimity, creating the risk of political paralysis with one member state blocking its application. Although proposals such as extending qualified majority voting have been advanced, they generally exclude military decisions in the realm of CSDP, leaving a significant gap between legal commitments and operational effectiveness. Furthermore, there is not yet an automatic role for EU institutions under Article 42(7), meaning that the crisis response, humanitarian emergency, economic security, critical infrastructure, and military mobility tools at the EU’s disposal could not technically be used once the clause is triggered.

Finally, any European defense union would need to define the role of key non-EU partners. Canada, Iceland, Norway, Turkey, the UK, and Ukraine would remain indispensable contributors to Europe’s continental defense. Although they cannot invoke Article 42(7) or access EU crisis management and financing mechanisms, nothing prevents them from supporting an EU member state through bilateral military assistance or participating in planning arrangements. Preserving those partnerships, especially the UK because of its nuclear capabilities, would therefore be essential if Article 42(7) were ever to become the foundation of a credible European security architecture.

By contrast, any EU institutional role in nuclear deterrence faces enormous constraints, including opposition from neutral and antinuclear member states, and the fact that nuclear capabilities in the EU remain exclusively in the hands of France. For that reason, a supranational European nuclear capability is as much fantasy as a supranational European army. A credible European defense union, if it were to overcome the institutional hurdles presented here, would rely primarily on the willingness of its EU member states to cooperate with each other on defense, including France and the UK on nuclear deterrence, supported by the institutions—not the institutions providing the defense themselves. For the time being, this approach would still rely heavily on the U.S. nuclear guarantee, not least because European nuclear alternatives driven by the French with British support still need time to mature.

Certain aspects of a European defense union might be welcomed by the United States, especially if the arrangement strengthens Europe’s conventional capabilities, improves defense financing and military mobility, and reinforces crisis response. The more fundamental question is how much European defense integration the United States would see in its interests and tolerate before it perceived a significant loss of political, military, and industrial influence in Europe. For U.S. strategic interests, this model would certainly represent the least desirable option. The United States could eventually become an outsider when it comes to Europe’s defense, with all the inherent risks and downsides.

Washington has long opposed EU initiatives that duplicate or decouple from NATO, and it may argue that the EU lacks both the leadership structure and strategic authority that the United States has traditionally exercised through NATO and SACEUR. Yet the very rationale for a European defense union presupposes a fundamental breakdown in transatlantic relations or NATO itself, whether through U.S. withdrawal or actions that undermine the alliance. In this worst-case scenario, Washington might not be able to determine which shape Europe’s defense takes. However, the United States would still exert significant leverage over a European defense union because it is presently the most effective nuclear deterrent against Russian nuclear forces, at least until a time when French and British nuclear capabilities can comprehensively protect all of Europe.