> If Russia were to physically disrupt a country's social services by force, it would be an act of war

If the Russian STATE did this yes. But we don't generally consider the act of citizens/organizations/criminal enterprises within a state as a state action unless it's clearly state sponsored. You definitely could make that argument, but it's not a given.

For example, we don't consider the 3000 British people fighting alongside Ukraine against the Russians [1] to be part of the UK state, so their fighting isn't an act of war either.

[1] https://news.sky.com/story/ukraine-war-3-000-british-volunte...