Russia just doesn't respect the West's ability to stop his efforts to rebuild the Russian empire--if not the Soviet empire.
So Putin mouths off about our plots secure in the knowledge that we aren't actually thinking much about them let alone plotting against them. We're the perfect enemy.
Just feel the respect the Russians have for us:
Russia’s deputy prime minister laughed off sanctions imposed Monday by the United States on 11 top Russian and Ukranian officials, questioning if the list of targets was drawn up by “some prankster.”
Ah, restoring our reputation abroad.
We'll see if Russia blatant violation of the territorial integrity of Ukraine, which Russia pledged to respect in the 1994 Budapest Memorandum, and which is the basis of the United Nations system of rallying the world to stop cross-border acts of aggression between member states, gets the West to rediscover the will to resist threats.
You'll notice that Putin is as meek as a kitten when he deals with China. They are not the perfect enemy.