[graemep]

There is no such thing as EU defence - EU states have their own forces. The main defensive alliance in Europe is NATO, and the most important NATO country is the US.

[type0]

For Northern Europe there's UK led JEF

https://en.wikipedia.org/wiki/Joint_Expeditionary_Force

[graemep]

Less important than NATO, and not EU either - 10 countries, six of which are in the EU, three including the lead country are not.