N Korea sends troops to fight with Russia: Seoul
bbc.com
bbc.com
Presumably North Korea is doing this in exchange for cash, oil, or other support from Russia. As tensions with South Korea are rising again, they might also want to give their soldiers combat experience.
I wonder what will happen, though, if many of their soldiers are killed or wounded fighting for Russia. Totalitarian dictatorships like North Korea can seem from the outside to be firmly entrenched and resistant to domestic political pressures. But a failed military adventure could lead to unprecedented pressure on the leaders who ordered it.