Putin was able to mobilize his army from the Russian Hinterlands.
But he's pretty much tapped out at this point. Which is why he had to ask the North Koreans to send some of their grunts.
The potential is there for Putin to mobilize even more troops but he'll have to conscript in Moscow and St. Petersburg.
He won't do that because he'll be at risk of getting overthrown.
Hope Trump succeeds in ending this insanity before it gets even worse than it already is.
He has made big strides in limiting the conflict as much as possible so far but if the Russians move on to unrestricted warfare the damage they will do to the Ukraine ability to execute a rapid post war recovery will be severely compromised and far more expensive.