Summary
North Korea is sending thousands of soldiers to support Russia in the Ukraine war, expecting compensation of $200 million annually. In return, Russia is providing North Korea with rice, advanced space technology, and potential military assistance in the event of a contingency on the Korean Peninsula.
Despite the the National Intelligence Service’s assessment that the costs outweigh the benefits, experts believe North Korea is securing a strategic advantage by aligning itself with Russia.
I doubt Russia would want that since NK is unstable and can easily point those weapons back at them at some point in the future.
Russian decisions over the past few years haven’t exactly shown much long-term strategic choices or forethought, so I doubt this is an argument for them