Seoul, South Korea ? The “Dear Leader” is ill and out of sight – at a time when North Korea is backtracking on a pledge to abandon its nuclear ambitions and is building a missile base that analysts say could put U.S. territory within range.

Some fear that the longer Kim Jong Il remains behind closed doors recuperating from an apparent stroke, the greater the risk of a political vacuum and implosion of the nuclear-armed state.

So far there is nothing to indicate trouble since word of Kim’s health problems reached the world – no unusual military moves, no surge of refugees, no disruption of trade between the two Koreas.

But in a country as opaque and secretive as North Korea, any surprise is bound to cause alarm and conflicting guesses.

Concerns spiked Tuesday when Kim failed to appear at a showpiece parade marking the 60th anniversary of North Korea’s founding.

South Korean news reports say he had a stroke about three weeks earlier, underwent brain surgery and was suffering some paralysis and spasms. The government in Seoul, well plugged in to events in the North, acknowledges he had a stroke, but says he is not incapacitated, is recovering and is in control.

“It appears that there is no leadership change” in North Korea, Defense Minister Lee Sang-hee told lawmakers Thursday during a closed-door briefing, according to Jun Eun-hye, aide to a lawmaker from the ruling party.

North Korea’s state media have been silent on Kim’s health, but his No. 2, Kim Yong Nam, took the unusual step Wednesday of telling Japan’s Kyodo News agency that “there are no problems.” A senior North Korean diplomat also told Kyodo that talk of Kim’s illness was a “conspiracy plot” by Western media. There have been no further comments.

The South Korean government and private analysts say there have been no signs of unrest.

The heavily armed demilitarized zone, or DMZ, that separates the two Koreas has shown no increase in tension, with soldiers from both sides observing each other as they normally do, sometimes just steps away as at the border village of Panmunjom. An Associated Press photographer who visited the DMZ Thursday also found nothing changed.

The Pyongyang parade that Kim missed was a scaled-down affair with no major contingents of regular troops and no heavy weaponry.

Paik Hak-soon, a North Korea expert at the Sejong Institute, a private think tank near Seoul, says the calm proves Kim is still calling the shots, despite any illness, and should be taken as good news.

“Kim Jong Il is the most reliable partner we can deal with,” Paik said. “He is in control.”

Kim’s departure would be a momentous event for a country that has known no leaders other than Kim – “the Dear Leader” in the constant propaganda fed to the nation – and his late father, Kim Il Sung, “the Great Leader.”

At the same time as its nuclear threat has mounted, it has engaged in detente and trade with South Korea, with two-way commerce soaring to $1.8 billion last year from $425 million in 2000.

The joint economic zone is an arrangement reminiscent of China’s early forays into capitalism, and in the past has raised the possibility that Kim was laying the groundwork for his successors to go the same route.

But no leadership succession has been revealed, there is no indication of reformers waiting in the wings, and right now, the prospect of a North Korea without Kim frightens some analysts.

“If Kim Jong Il disappears, there is a significant chance that the entire regime will collapse,” the conservative mass-circulation Chosun Ilbo newspaper said in an editorial Thursday. “If that happens, it is difficult to predict what North Korea’s 1.17 million-strong military, armed with nuclear, chemical and biological weapons, will do next.”