Butterflies, man, remember the butterflies! Assuming even that the French Revolution occurs roughly on-schedule with a point of divergence somewhere in the 17th century, any different Scandinavian involvement different at all from OTL-- likely, considering the factors behind the Battle of Copenhagen and all that-- would easily change the outcome of the war. Assuming that even that stays mostly the same, who's to say that a united Scandinavia would mean that Prussian unification of Germany would go along according to schedule? Would Wilhelm II even be born in such a timeline? Would there even be a World War One, much less one that starts in 1914?If there was a sizeable Scandinavian Empire to the north during the 17th-18th Centuries, what sort of role would it have played during the Napoleonic Wars later on? The Scandinavian states had a limited impact on the conflict and Sweden for quite a sustained period followed a policy of 'armed neutrality'.
A developed and industrialised Scandinavia would perhaps have a say in German unification.....and in the process, could we have seen Scandinavian armies on the Eastern Front in 1914.....siding with...who?
Butterflies, always remember the butterflies!