Some Russians claim to have started
an anti-Putin armed guerrilla movement
operating in Russian territory.
However, they seem to have entered Russia across the Ukrainian border,
and to have picked up some US-made arms in Ukraine. So far they have
attacked only government targets.
In moral terms, I think what they are doing is admirable. Their
actions could help Ukraine win the war, but I think it will be
difficult to increase them enough to have a significant effect.
Putin could theoretically cite this as an excuse for attacking Ukraine
in some new ways. But I don't think that makes any difference. Putin
never needs a real excuse for any atrocity — he invents all the bogus excuses
he needs.