The dust has far from settled on the death of Kim Jong Nam in Kuala Lumpur International Airport on Monday, February 13, but there is a growing sense that the killing of the half-brother of North Korean dictator Kim Jong Un reflects worsening instability in Pyongyang.

Kim Jong Nam, the 45-year-old first son of former leader Kim Jong Il, had famously fallen out of favor with his father after being detained by Japanese officials at Tokyo's Narita International Airport in April 2001 for travelling on a forged Dominican Republic passport.

He told his interrogators that he was planning to visit Tokyo Disneyland with his family.

In exile in Macau and Beijing, he largely kept a low profile as family politics went on as normal in North Korea, feeding his appetite for mistresses, gambling and fine dining with funds provided by his uncle, Jang Song Thaek, who was once considered to be the country's second-most powerful person.

That source of funds came to a sudden halt in December 2013 when Jang was spectacularly arrested by Kim Jong Un and tried on a raft of charges, including attempting to subvert the regime, leading to his execution.

A warning

Jang's summary execution could only have served as a warning to Kim Jong Nam and almost certainly made him reconsider his options.

Analysts say that there were a couple of possible courses for Kim. He could have continued to live under Chinese protection, with the suggestion that Beijing considered him to be a fall-back leader should Kim Jong Un fall victim to a coup or an assassin.

Alternatively, they say, he could have taken the plunge and defected to South Korea or another country, and there are reports that he met with representatives of the South Korean government to discuss moving to Seoul.

One such rumor surfaced only last week and may have been the final catalyst for Kim Jong Un ordering his death. To have a son of the Kim line publicly defecting to South Korea would have been simply too much for the regime in Pyongyang to bear and would have thrown its legitimacy open to doubt.

And right now, observers say, the last thing that Kim Jong Un needs is new unrest and questions about his legitimacy to rule.

"Of all the reasons for Kim to order his half-brother's death, that to me is the most compelling one," said Rah Jong-yil, a former head of South Korean intelligence.

"It would have been a huge propaganda coup for the South and there have been rumors that his defection has been discussed," he told DW.

No longer sealed off

"His half-brother's defection would have just added to the instability that we hear about in the North," Rah Jong-yil said.

"It is no longer hermetically sealed from the rest of the world because more cell phones, memory sticks and discs are being smuggled in from the outside.

"The people are beginning to see for themselves what life is like elsewhere, and particularly in the South," he pointed out.

"Also, Kim Jong Un does not really have anything to be proud about since he became leader, except more nuclear weapons, which does nothing to improve the ordinary citizen's life," Rah added. "That breeds disaffection.

"People are becoming more restless and we can also see that in the number of defectors in the last year or so, both the increasing number of ordinary people risking everything to get out and the members of the elite, the high-ranking party and government officials doing the same."

Toshimitsu Shigemura, a professor at Tokyo's Waseda University and an authority on North Korean affairs, agrees that the defections have harmed Kim's standing at home, and particularly that of Thae Yong-ho, who last July fled the regime's London embassy with his family and was spirited away to Seoul.

"All these defections are causing utter turmoil in the corridors of power in North Korea because it turns out that Thae was only able to get his whole family out by bribing the head of the secret police in Pyongyang as well as the secret police officials tasked with overseeing him in London," Shigemura said.

Secret police purges

When Kim Jong Un discovered the truth, he dismissed Kim Won Hong, the head of the state secret police, and purged dozens of lower-ranked members of the organization, Shigemura added.

The downside of that action is that he is fostering further resentment towards his leadership among some of the country's most experienced and long-serving officials. That bitterness, he suggested, could very easily turn into hostility aimed at Kim Jong Un personally and, ultimately, a coup.

"Kim has very few friends right now," Shigemura pointed out. "He rules through power and fear, but he no longer has good relations with China or Russia and has alienated key subordinates and organizations.

"He may have thought that Kim Jong Nam might be seen by some of them as a potential replacement at the same time as continuing the Kim bloodline," he added.

"He may have got rid of that particular headache by ordering his assassination, but he is no more stable now than he was before."