I love, well not love, but see all the irony and 1984 style double speak in it all.

Nord I & II were civilian infrastructure to help ensure Europe's energy needs looking into the future. The more options available the better. Best not to put all your eggs into one basket. Good capitalist endevour, providing competition and cheaper energy to consumers. To European societies.
This somehow was interpreted and turned around, sold as Europe being dependent on this one source of many options still. So they then spite themselves by refusing to use that energy option, causing an energy crisis with more insecurity and dependancy on remaining options.
Now Nord I & II are gone as an option altogether via sabotage with explosives, with the technical ability to pull it off suggesting state actor.
If a military act, then taking out essential civilian infrastructure in international waters has nothing to do with national defense. It has everything to do with economic power ie corporate power. When states choose to use their military in this way, representing corporate interests rather the interest of people......they have a word for that type of governance.
And the best irony is it will alway be cheaper to transport energy to Europe from Russia than anywhere else outside of Europe due to geography.