His legitimacy is based on the lingering respect for his father. This is also, perhaps, why he keeps his next-in-line out of site - to keep himself enshrined and base his son's legitimacy on himself.

Kim . . . doesn't want foreign interference in succession, or for foreigners to try to cut deals with his chosen successor instead of himself.

Chaos in North Korea is still seen as the most likely scenario for some 'adventurism' with conventional or nuclear weapons.