So, in most timeline I've read, the Scandinavian countries in 20th century very rarely involve themselves at war unless they're invaded, and they never seems to be aggressive.
But still, after some discussions, most said that to have an aggressive scandinavians, we need pre20th Century POD(s).
And well? What could bring modern viking raiders back then?
Note : Scandinavian countries in personal union with German/France/Britain/Russia/any non scandinavian nation didn't count. But union/annexation by another scandinavian countries count.
Could be Denmark, Norway, Sweden, or even Finland...