This recalls the civil war in Spain during the 1930’s.
Germany and Italy were fighting a proxy war with the Soviet Union on somebody else’s real estate, the “Republicans” (backed by the Soviet Union) against the Spanish Falange (supported by the Italian Fascists and the German Nazis).
Everybody involved had to be some kind of socialist, but it was an excellent test bed for trying out various military hardware and tactics. The Spanish Falange (under Franco) sat out the Second World War, but was still a conduit for assistance to the Axis powers.
North Korea is a place to try out a test bed of various Russian Federation designs. Russia and China do not always have the easiest of relationships, and this is as much between Russia and China as it is between the US and North Korea.
There is a secret struggle going on we are not seeing.
Yet.
Sat out-ish. Spain sent the 'Blue' Division to Russia after Barbarossa and withdrew it when it looked like Germany would lose.
They also made good money selling tungsten to the Axis which was needed for armor and hardening AP shells.