Foreign Military Sales (FMS) notifications are official announcements through which the government notifies Congress of proposed arms exports. Each notice lists the systems, components and technologies to be exported, providing a detailed record of US defense exports. What looks like a bureaucratic process is actually a revealing map of military dependence.
In new research, we have created a database that includes every FMS alert from 2008 onwards. The database, available at Bruegel, the European economic policy institute, allows for a reassessment of European arms imports from the US. The findings challenge the common perception of overwhelming dependence. Overall, Europe imports only a limited percentage of its defense equipment from the US. Most European countries have maintained or even increased their own military production in recent years.
The real vulnerability lies elsewhere: in specific, high-tech systems essential to modern warfare. These include battle management software, missile defense architectures and secure data exchange networks.
The F127 frigates and the possible “kill-switch”
A striking example is the German F127 frigate program. Germany is spending billions on new ships to be built in European shipyards, but their combat system will be based on US Aegis software — the digital core that integrates radar, targeting and missile interception. Without Aegis, the frigates’ advanced air defense capabilities would be severely limited.
Such cases highlight a broader structural issue. Modern weapons are no longer static; they are software-based systems that require regular updates, data connectivity, and often remote maintenance from the original vendor. This creates the so-called “kill-switch problem” — the theoretical possibility for a vendor to limit or even disable a system’s functionality, for example by not providing software updates. Even if such action between allies is unlikely, its mere existence gives the US leverage.
Addiction, after all, need not be exercised to be effective. The awareness that advanced European systems depend on American technology can subtly shape interactions far beyond the military — from trade negotiations to issues of industrial policy or export controls. In recent trade negotiations between the US and Europe, top European politicians and officials have openly admitted that security dependency has affected the deal.
Immediate need for a long-term plan for Eurodefence
The answer must not begin with grandiose new programs, but with careful analysis. Europe needs a clear empirical picture of what its critical dependencies are — technological, contractual and political. The new FMS database provides a first step in this direction. In the next step, policy makers must develop a medium-term plan to reduce dependencies that are deemed unacceptable. This work must begin immediately.
A particular challenge for rulers is that they cannot rely on their military for an objective assessment. The armed forces in Germany and elsewhere have long operated within the framework of NATO and trust their American counterparts almost blindly. This confidence is understandable at the military level, but it ignores politics. The political risk to military cooperation arising from the Trump administration is too great to ignore, as Ukraine has been forced to realize. When he was cut off for two weeks by American intelligence, he suffered heavy casualties. Political planning in Western Europe must now begin to work on the unthinkable. Europe cannot continue to depend on the US for security-critical technology.
* Mr Guntram Wolff is a professor at the Solvay Brussels School of Economics and Management at the Université libre de Bruxelles and a senior fellow at Bruegel, of which he was director 2013–22. Mr. Juan Mejino-López is a research analyst at Bruegel
