> But the proposals in the article defining "subversion" to include environmental activism, independence movements, or criticism of UK policy show how quickly these things expand beyond their original scope.

Yes, but I wouldn't put "independence movements" in that list. Much as I'm relaxed about the Welsh and Scots' independence movements, for Northern Ireland to do whatever it wants including the current kicking-can-down-road approach, and for any future potential from the Cornish and London vague aspirations that nobody currently takes seriously…

… if I was a hostile foreign power, then I would absolutely support all of those campaigns. And more. (Independence for Langstone! :P)