North Korean leader Kim Jong-un has not been seen in public since September 3. And today for the first time he did not take part in the annual commemoration of the foundation of the Korean Workers Party.

Meanwhile, on October 3, three of the highest ranking officials in the country made a surprise visit to the closing ceremony of the 2014 Asian Games in Incheon, South Korea, when they agreed with senior South Koreans to resume the inter-Korean dialogue that has been suspended for years.

It is strange for Kim to be out of view for this long; while he's avoided public appearances in the past, he's never done so for a whole five weeks. It's even stranger that North Korean television told viewers that Kim is "suffering physical discomfort." Normally North Korean media simply do not discuss the health of the leader.

Senior defectors have said that for some time Kim Jong-un has been a public figurehead while the real power has been exercised by the shadowy Organization and Guidance Department of the Korean Workers Party.

The visit to Incheon too was strange for several reasons. It is most unusual for North Korea to make unannounced visits of this kind, let alone visits by such senior officials. Moreover, as a senior defector has pointed out, the visitors' behavior was odd. They smiled and chatted, which North Korean emissaries are not supposed to do. The delegation leader appeared in a military uniform, which North Korea regards as a concession for special occasions. The delegation arrived with bodyguards, a privilege normally reserved in North Korea for the top leader, and did not gush the kind of praise of Kim Jong-un that would be expected.

So what is going on? Nobody outside Pyongyang knows for certain — and perhaps not many people in Pyongyang know either. But we may be witnessing significant change in North Korea.

It seems unlikely that Kim's absence really is due to poor health. If, as has been rumored, he fractured his ankles, he could still have been filmed seated at the recent session of the Supreme People's Assembly that he missed. Even if he were so seriously ill as to be unable to appear for all this time, the regime could have disguised the fact, as it did when Kim Jong-un's father, Kim Jong-il, was sick.

It seems more likely that his absence is due to politics, not health.

If Kim Jong-un has indeed been shunted aside, then whoever has replaced him has not moved into the limelight. Nobody has taken his place in visits to factories and military units — these visits appear simply to have stopped. Some have suggested that he has been effectively replaced by his younger sister, Kim Yo-jong, (who, as a mere woman, would not be seen as a credible public figurehead in North Korea), but the evidence for this seems very slight. On the other hand, senior defectors have said that for some time Kim Jong-un has been a public figurehead while the real power has been exercised by the shadowy Organization and Guidance Department (OGD) of the Korean Workers Party, which was created by his father as a secretariat.

To hazard a guess as to what has happened: It is possible that the OGD has decided to remove Kim Jong-un as a figurehead.

There are seemingly reasons to do so. North Korea has struggled for more than a year to find a source of money to replace aid from China that was reduced following North Korea's third nuclear test in February 2013. The regime probably needs that aid to secure the political loyalty of the Pyongyang elite. Although they now enjoy much better access to restaurants, coffee houses, and consumer goods than they did just a few years ago, they have been steadily learning how poor they are compared to the Chinese — let alone the South Koreans — and demanding more goodies that the regime is struggling to provide.

The regime has tried to secure significant investment from Russia, and senior North Korean officials have toured other countries in Europe trying to find money there too. Both efforts have failed, and it is hard to see where the regime could now turn for financial assistance other than to South Korea. Perhaps Kim resisted reaching out to the arch rival, and the OGD decided that, for the regime as a whole to survive, Kim had to go.

Some have said that if there were a coup, bloodless or otherwise, then we should observe movements of people and of the military that do not seem to be occurring. A classic coup might provoke such movements, but a silent takeover by the OGD probably would not. The North Korean military are under the command of the Korean Workers Party, and if the OGD decided to take Kim out of the limelight, it would be simple to instruct the party to order the military to carry on as usual. And with the OGD continuing to run the country, it would be business as usual for North Korean civilians.

If this hunch is correct, then it is not surprising that the delegation to Incheon behaved atypically. For grizzled senior cadres used to a lifetime of kowtowing to the Kims, their first visit abroad without having to answer to the dynasty would have felt like a liberation. They even got to fly in Kim's personal plane.

The visitors to Incheon did not bring a letter from Kim, which some have seen as a sign that North Korea is not yet serious about improving relations with the South. But perhaps there is another explanation.

Perhaps Kim Jong-un is simply not writing letters anymore.