It is about scale. My country Norway was under Danish rule for 400 years, yet it was never anything like the oppression and brutality the Scottish and Irish experienced at the hands of the English. It is why despite Scandinavian having fought numerous wars agains each other, there is not much bad blood. None of the wars were really that terrible.

Telling was how Sweden and Norway fought when Norway declared independece in 1905. It did not last long because the Swedish king did not want to make Norwegians hate Swedes. Not the kind of thing that would ever have concerned and english king or people like Bismarch.

There were complex aspects about both those wars. But they were indisputably fought between Danes and Germans. Schleswig-Holstein was a German duchy under the Danish king, not a paart of Denmark proper.

The second war, in 1864, ended with a huge loss of Danish territory to the emerging German superstate. The northern half of this territory was returned to Denmark in 1920, with the southern remaining German. This was the result of a referendum in the wake of World War 1. Everything was orderly and civilized, and the border region to this day remains a model of how to handle such things without undue upheaval - thus exactly confirming my point above.