I thought we'd settled this ages ago, they don't and no he can't.
Russia aren't drawing up plans to conscript another 500,000 men because they've got loads of troops sitting around waiting to be called upon.
They aren't holding anything back. This is the extent of Russia's military power.
The US estimated that the invasion force was 80% of Russia's ground force, and 100% of that had been deployed by late March. There's no one hiding in the wings, no secret supply of armor they were holding back for the first 350 days of the 3 day war.