European defence union has moved from long-running Brussels debate to an explicit political proposal after EU Defence and Space Commissioner Andrius Kubilius called for a new framework that would allow Europe to act more coherently on defence, including with non-EU partners such as Norway, the United Kingdom and Ukraine.
Speaking in Brussels on Friday at the annual conference of the European Commission’s Legal Service, Kubilius argued that the European Union should be ready to defend itself “as Europe”, not only as a group of 27 member states. He said the current EU treaties are not sufficient to build the level of defence integration now required by the war in Ukraine, the Russian threat and growing doubts about the long-term reliability of USA security guarantees.
Kubilius wants a treaty beyond today’s EU framework
Kubilius’s intervention matters because it goes beyond the familiar call for “more cooperation” on defence. He is arguing for something more structured: a new intergovernmental treaty that could underpin a “genuine European defence union” and bring in closely aligned non-EU countries.
That would mark a significant political step. The EU already has defence tools, joint procurement schemes and bilateral security and defence partnerships with countries including Norway and the UK. But those mechanisms stop short of creating a single European defence structure with a stronger common legal basis and a broader strategic chain of command.
In practice, Kubilius is pointing to a model that would sit alongside existing EU instruments and NATO rather than replace them. For supporters, the idea reflects a new geopolitical reality: Europe can no longer assume that Washington will always provide the same military backstop, especially under a USA administration that has repeatedly pressed European allies to do more for their own security.
Why Norway, the UK and Ukraine are central to the plan
Kubilius explicitly included Norway, the UK and Ukraine in his vision. That is politically significant for three different reasons.
Norway is outside the EU but is already one of Brussels’ closest security partners, with an EU-Norway Security and Defence Partnership signed in 2024. The UK, despite Brexit, has also moved back into structured defence cooperation with the EU through a security and defence partnership agreed in 2025. Ukraine, meanwhile, has become central to the continent’s military and industrial future because of the scale of the war, the speed of battlefield innovation and the wider question of Europe’s eastern security architecture.
Bringing those three countries into a more formal defence structure would therefore reflect the real map of European security rather than the legal borders of the Union alone. It would also acknowledge that the northern and eastern flanks of Europe are increasingly interconnected, from the Arctic and North Atlantic to the Baltic and Black Sea theatres.
A European defence union would face legal and political obstacles
For now, the proposal remains political rather than legislative. Kubilius himself acknowledged that a deeper arrangement would require legal and constitutional changes, because the existing treaties do not provide an adequate basis for the type of defence union he is describing.
That makes the idea ambitious and potentially controversial. Treaty change is difficult inside the EU, and a parallel intergovernmental pact would raise questions about governance, democratic oversight, financing, command structures and the relationship with NATO. Some member states would also be cautious about anything that looks like duplication of the Atlantic alliance, while others may resist giving Brussels or a new European structure more influence over military policy.
There is also a strategic question behind the legal debate: whether Europe is ready to move from a defence market and coordination agenda to a more explicitly political and operational concept of collective defence capacity.
The proposal fits a broader shift in EU defence policy
Even so, Kubilius’s remarks do not come out of nowhere. Since 2025, the EU executive and member states have been building a stronger defence agenda through the Readiness 2030 white paper, new financing instruments and efforts to expand industrial capacity. Kubilius has been publicly arguing for a European defence union for months, including in speeches to the European Parliament earlier this year.
What is new is the sharper language and the clearer institutional implication. The commissioner is no longer speaking only about better coordination or more spending. He is openly suggesting that Europe may need a new legal architecture for defence if it wants to respond credibly to Russian pressure, support Ukraine over the long term and reduce its strategic dependence on USA capabilities.
