By Becky Branford
Kim's absence sparked intense speculation over his wellbeing
The absence of the North Korean leader, Kim Jong-il, from celebrations marking the 60th anniversary of the country's founding triggered a frenzy of speculation.
Several analysts suggested he had died, others that he was incapacitated.
The conclusion reached by South Korea's intelligence service on Wednesday was that he had suffered a stroke, but was still capable of running the country.
Some say all this speculation about Mr Kim's health was an overreaction.
But many others have pointed out that the rumours raise a very important point - one day Mr Kim will die or become unable to govern; does the world have a plan for what to do then?
There have been repeated suspicions that Mr Kim suffers a serious illness - bolstered by the impression that he has seemed weak and overweight in his last few appearances in public.
Along with a stroke, South Korean intelligence sources suggest he also suffers from diabetes and heart disease.
North Korea has coped with the death of a leader once before - in 1994, when Great Leader Kim Il-sung died.
But analysts say that was different. When Kim Jong-il took over from his father, he had long been groomed as a successor.
This time, "the children are young and with no obvious experience in terms of managing anything", Hazel Smith, North Korea specialist at Warwick University, told the BBC's Today programme. None has been officially recognised as a successor.
Amid the vacuum, there have been reports of an embryonic power struggle within the North Korean elite.
It is dominated by three main groups: the Kim family, the Korean Workers' Party and the armed forces.
Lee Chung-min, professor of international relations at Seoul's prestigious Yonsei University, says any new figurehead would probably be nominated by the army but "would immediately have to share power with the family and party".
"Such an unstable three-legged stool," he said, "won't last long".
There have been big changes in North Korea in the 14 years since Kim Il-sung passed away.
A devastating famine and economic collapse have - to an extent - loosened the government's suffocating hold on its people, particularly in cities and in border regions. Private economic activity has blossomed as state provision has failed.
But there are tensions within the army over whether to continue with such reforms, according to Professor Smith.
"There are elements in the military [who] want to see modernisation and more contact with foreigners, because they can see ways of making money and rebuilding the military," she said.
There are also splits in North Korea's powerful military
"But there are also parts of this huge military who want to go back to the old nationalist project. It looks like it's going to be those different points of view within the military who will be battling it out for the future of North Korea."
For Leonid Petrov, North Korea historian at Australian National University, this tug of war over reforms is key to how North Koreans will respond to the demise of Kim Jong-il.
He says the population was badly traumatised by the death of Kim Il-sung - partly because of the personality cult which surrounded him, but partly also because it heralded a period of intense isolation and impoverishment in which more than a million people may have died.
Dr Petrov suggests any internal candidate able to preserve short-term stability would probably be more conservative than Kim Jong-il.
But he warns against any such candidate attempting to roll back the economic reforms that have allowed North Koreans a little more room to make an independent living.
Small protests have been reported in areas where local officials have attempted to rein in private trading - and such protests could snowball.
That could be a central factor in how durable any successor regime proves to be.
It is, of course, difficult to assess what preparations have been made in Washington, Beijing and Seoul for a succession crisis in North Korea, because governments do not often reveal details of their contingency planning.
But the picture painted by analysts is a gloomy one.
While South Korea is certain to have spent decades planning for this eventuality, Dr Petrov points out that they face the serious problems of a lack of a plausible opposition to the North Korean regime and no convincing candidate for leader either inside or outside the country.
In Washington there are accusations of lack of planning over North Korea from people as senior as Victor Cha, former North Korea adviser to President Bush.
In an article in June, he wrote: "Given the stakes involved, you would think that the US, South Korea and other regional partners had some type of agreed upon plan. Nope."
He cautioned that a "quiet discussion among concerned governments about how to deal with potential North Korean instability" was needed "before the next rumour turns out to be true".
The impact of what happens inside North Korea's borders is not confined to North Korea.
The country may possess nuclear weapons.
Failing social provision within North Korea has already sent thousands of humanitarian refugees streaming beyond the country's borders - mainly into north-eastern China. A leadership crisis could turn this stream into a flood.
Sitting between China, Russia, Japan and South Korea, North Korea is situated in a place of extreme geopolitical importance.
Even if Kim Jong-il is still alive and well, these rumours of his ill health may prove to be a useful wake-up call.