I hope you're right that Putin wants no part in a conflict involving the DPRK.
Regarding Putin:
1. South Korea's GDP is 11th place world wide, Russia's is 12th.
2. Russia is already involved in the Ukraine and Syria. South Korea has been preparing for NK for 60 years.
3. Russia has geographically limited access to NK, and is in fact closing off Vladivostok's port.
4. NK is not as important to Russia as it once was.
5. Russia no longer has any military advantage in fight on or near the Korea peninsula.
Putin is shrewd enough to know when fold and get out of the saloon.