South Korea, too, millions of Nork refugees pouring over the border.
Maybe, but that would be far more risky than fleeing to China. Most of the Nork population is in the north and most of the DMZ is heavily mined/
It wasn't West Germany that was destabilized by Ossis heading west. South Korea is willing to accept every single NK refugee. It has petitioned China to let North Koreans in China move to the South. China has refused, because the mass movement of North Koreans to South Korea would have the same effect on North Korea as the end of the Berlin Wall had on the Warsaw Pact countries - the collapse of the Kim dynasty and NK's communist government. Since the outright annexation of North Korea by China would trigger a war with the South, the Chinese are doing the next best thing - keeping their vassal Kim economically afloat by sending him aid, and demographically afloat by not allowing North Korean refugees to move to South Korea.