Hm, but pre-wwI was there even a communist (or revolutionary socialist) organisation in Denmark? In Sweden there wasn't, the revolutionary socialists and reformist socialists was in the same unions and the same party.

So I think treating the soc-dems as something static over a hundred years are wrong.

Then the effect of the cold war and the communist bloc, I think was that the right by and large in the anglo world and western Europe (with exceptions) turned left and accepted soc-dem governments and social reforms. Without threatening civil war or coups.

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