The Joint Expeditionary Force – a UK-led defence cooperation format of ten European countries – has gained political momentum since the Russian invasion of Ukraine in 2022.

Since the late 2010s, the JEF has shifted its focus towards hybrid issues, increasingly in Northern Europe. While its role in the hybrid sphere is potentially fruitful, the JEF should be wary of taking on too wide a range of tasks.

The JEF’s role as a “sub-threshold” actor could complement NATO’s collective defence efforts below Article 5. Hence, the JEF should be more coherently integrated into the Northern European security architecture. Obstacles to JEF-NATO integration have now been removed, as all JEF nations are also members of the alliance.

A more explicit division of labour between the JEF and NATO would help Northern European countries to handle the current security environment comprehensively. Such a security architecture, covering all dimensions of the conflict spectrum, would be particularly beneficial for Finland, which shares a long common border with Russia.

Visiting Research Fellow