They don’t need it any more. Arms exports to Russia are far more profitable.
I believe they are going to attack the moment China can or does not want to stop them anymore.
A Korean War would bind a significant amount of US resources. To Russia it could be very valuable at the time that they decide to seriously start messing with NATO countries.
Despite how much it pains me to admit that George Bush was right in one thing: There is an axis of evil. And it is getting ready.