No one is going to attack North Korea and despite promising to do so every minute of every day for the last few decades North Korea isn’t going to attack anyone. Russia on the other hand is a typical warmongering western imperial power squabbling with the other warmongering western imperial powers like always, so they will be having wars to spare for as long as there is a Russian Federation. I guess NK trading a few million extra mouths to feed for whatever Russia can spare economically could benefit the leadership of both countries.