It's an interesting and informative article (its origin notwithstanding), though its biases shine through in some places. Characterising Finland as a mere Soviet satellite state, as the article does, is a gross oversimplification at best or an outright falsehood at worst. The author is perhaps a bit too stuck in a Cold War frame of how things are.
But anyway, to get to the nutmeat of the article, the economic perspective. That drives a lot of cooperation (yes, there's that word again!) in the Nordic countries, more so than some romantic ideals of "brother nations". Sheer pragmatism, really.

"The basis of optimism is sheer terror" - Oscar Wilde