Pfff... sure. Just make Putin's elites families and relatives, who live in EU and Britain pay for all the damage from these "unknown sources" attacks. Those attacks will end immediately. Just recent known case - oligarch Altushkin supplying Russian ballistic missiles with electronics -but his wife and kids are in London.

Here what i think - "Hybrid" action under pretext of something dumb, for example "official war declaration", that includes - some mobilization effort - without any announcements, but through already existing systems like digital conscripts registers, but numbers will be far less than 100 of thousands. Some here, some there - just sending those letters to unfortunate ones all over the country. Probably dragging Belarus into conflict with open military actions against Ukraine (if war is declared officially - allies are obliged to help according to Russo-Belarus agreements), not too active but enough to hold some of Ukraine forces engaged in a fight on the north. And the main thing - far more repressive and tough regime inside Russia itself. Repressions, no internet for weeks and months at all, probably there will be some kind of obligatory labor for some segments of the population. Food stamps, maybe some other "military" measures for products distributions. And of course much more repressions and arrests. Tougher regime inside Russia itself is the main thing in my opinion.