I seem to recall that this is optimal game theoretic strategy - don't initiate, but always immediately retaliate.
Whatever is happening now is payback for Putin's birthday present to himself from 2 days ago, firing a missile into a Ukrainian apartment building that killed 22 civilians (mostly women & children).
I think the Wildberries strikes were a unilateral escalation on the part of Ukraine and the current escalation cycle has ensued from that.