Kim Jong-il looks poised to be the last North Korean leader to enjoy a semidivine status and rule the nation single-handedly.
No matter how well Mr Kim purges internal opposition, his youngest son will have to rely on a politburo of party and army officials if he takes power, amplifying the risks of infighting in the nuclear-armed state.
South Korean spies said this week the communist nation's parliament and army had pledged allegiance to Kim Jong-woon, the dictator's Swisseducated youngest son, who is believed to be only in his mid-20s.
It is unlikely he can even become a "Dear Leader" like his father. Cult-status reduces with every step taken away from the "Great Leader", Kim Il-sung, the nation's founder who is celebrated for his guerrilla battles against the Japanese in Manchuria in the 1930s.
"The cult system cannot go on through the third generation," said Kim Tae-woo, researcher at the Korea Institute for Defence Analyses in Seoul. "For the cult system to be established, three things are necessary - power, personality and policy. But Kim Jong-woon is now only his 20s, so it's hard to expect the three Ps from him."
North Korea's leaders rule by the Confucian notion of "mandate of heaven". In state media, the firmament often expresses its pleasure with rulers via a rainbow or comet.
"It is difficult to expect personal worship for Kim Jong-woon like that for his father and grandfather," Kim Tae-woo added. "If Kim Jong-il falls now, the most likely scenario will be a politburo system centred around senior military and party officials, which is likely to cause a power struggle."
Many political analysts have seen a flurry of military activity as a show of force by Kim Jong-il, who probably had a stroke last year, as he seeks to ward off any challengers to the succession of his dynasty.
Daniel Pinkston, North Korea expert at International Crisis Group, said: "They are not ready to execute a war. Kim Jong-il is testing loyalty, screening people to see who is really dedicated. He is a master of this." In the case of his father's sudden death, Kim Jong-woon would have little immediate weight. Kim Jong-il, by contrast, had been active in politics for 30 years before the death of Kim Il-sung in 1994.
Kim Jong-il will have ensured that his favoured son has mentors. Chief among these is Chang Sung-taek, his brother-in-law and canny political veteran. But James Shinn, the former Central Intelligence Agency senior analyst for east Asia, said the big question was whether the North Korean apparatus would allow the son to take over.
"It depends on the transition process - does Kim senior get to hang around and gradually 'hand him over' to the key folks in the apparatus, the way Kim Il-sung did?" asked Mr Shinn.
He said that scenario would make it easier for Mr Kim systematically to build a support structure for his son, which would be more difficult the earlier he passed away. "I think the insiders would just as soon turn on him if Kim senior dropped dead suddenly, or had another stroke [which is the most likely scenario]," said Mr Shinn.
Almost nothing is known of the characters of the military top-brass whose powers have been steadily growing under Kim Jong-il.
Choi Choon-heum, senior researcher at the Korea Institute for National Unification, said: "I expect the transfer of power will be smooth while Kim Jong-il is alive. But after his death, it will be a collective leadership backed by the military with Kim Jong-woon as a titular leader." .
Additional reporting by Song Jung-a and Demetri Sevastopulo.
