North Korea by the 1980s had an economy heavily depended on Soviet subsidies. In the 1990s with the collapse of the USSR, it lost those subsidies and was surrounded by US-friendly non-Communist Russia, Reformist China which provided limited aid and US backed South Korea. The loss of Soviet subsides led to famines which might have killed over a million North Koreans in a relatively small country.
Under those circumstances, one would have expected the regime to collapse in almost any AH scenario, especially since far more stable Communist regimes collapsed all over the world, is the survival of the DPRK an "ASBish" event?