The regime in NK persists because a great power (namely, Beijing) does not want an ally of the West on its border and is willing to spend the lives of 100s of 1000s of its soldiers to prevent that from happening (as illustrated by Beijing's choices during the Korean War).
Iraq, Libya or Lebanon don't have that advantage (and Kiev would get that advantage only if switches to being pro-Russian).
Iraq, Libya or Lebanon don't have that advantage (and Kiev would get that advantage only if switches to being pro-Russian).