North Korea poses no immediate threat in the aftermath of the death of leader Kim Jong Il, but the regime might well conduct a third nuclear test this spring, according to a panel of Asia specialists who spoke at the East-West Center.

While Kim’s successor — his 20-something son, Kim Jong Un — is largely unknown, his appointment was intended to create continuity, not change, they agreed.

“I don’t think we’re going to see sudden collapse and instability in North Korea,” said Michael Green, a visiting East-West Center fellow and senior adviser at the Center for Strategic and International Studies (CSIS) in Washington, D.C. “There is going to be an inward turn, there is going to be a period of mourning, and the soonest that we may start seeing some sense of this guy, I think, is in the spring and summer of next year.”

The North Koreans have for years announced that 2012 would be the year that they become a “strong and prosperous state” with nuclear weapons, a goal tied to the April centennial of the birth of founder Kim Il Sung.

“I think what we know about their program suggests pretty strongly that they are preparing for a third nuclear test and maybe missile tests,” said Green, a professor of international relations at Georgetown University who served as senior director for Asian affairs at the National Security Council from 2004 to 2005.

He spoke Tuesday at a panel discussion, “North Korea: An Uncertain Transition,” at the center’s Burns Hall. The other panelists were Ralph Cossa, president of the CSIS-affiliated Pacific Forum; Raymond Burghardt, former ambassador to Vietnam, former deputy chief of mission in South Korea and director of the East-West Seminars program; and center President Charles Morrison.

In the longer term, the panelists said, the power transition may well unravel, and Cossa predicted that Kim Jong Un will be the last leader of the communist North.

“I have a hard time believing that … the North Korean state will survive as long as Kim Jong Un,” he said. “I think he is clearly the last leader of that country. It’s going to at some point dissolve and be absorbed into the South. But nobody knows how that is going to occur, just like everyone knew at some point the Germanys would reunite but to predict when the wall was going to fall, I think, was a very difficult thing.”

The United States should continue considering the provision of food aid to North Korea, where hunger is widespread among the lower classes, and should pursue a resumption of the six-nation talks aimed at ridding the North of its nuclear programs, the panelists said.

But Cossa said the goal of the stalled six-party talks, involving the United States, South Korea, North Korea, China, Russia and Japan, has changed.

“They used to be to make things better — to de-nuclearize,” he said. “Now I think the objectives, if they resume, are to stop things from getting worse, in other words, to try to sort of hold things in place. There is an assumption that when the North Koreans are talking, they are not shooting.”

North Korea carried out two deadly attacks on the South last year, the first the sinking of the naval ship Cheonan, killing 46 sailors, and the second an artillery barrage at Yeonpyeong, a coastal island near their shared border, killing four.

“The likelihood of armed provocation in the immediate future is probably fairly low,” said Burghardt, “but it’s not at all clear whether this transition plan is going to work or not.”

Acting as regent to the young leader is Jang Song Thaek, who is married to Kim Jong Il’s sister, Kim Kyong Hui.

Perhaps the earlier chance to gauge the transition will be the official mourning ceremony Wednesday, Cossa said. Photos of the event will be closely scrutinized, much as with the Soviet Union during the Cold War, “to see who’s sitting where, and who’s next to who and what does all of this mean,” he said. “And we’ll have a great game of speculation at the time as to who is really in charge.”

If Jang lasts as regent, there is a chance he could lead the nation into Chinese-style economic reform, said Cossa.

If the regime ultimately does collapse, it won’t be from a people-power revolution but rather a revolt of the well-to-do, Green and Morrison said.

“The end of the regime is more likely to come from this small elite as they face difficult choices,” said Morrison.

But unification will be extremely difficult, Green warned.

He recalled jogging early one morning in Pyongyang, the North Korean capital, and seeing a phalanx of children, age 5 to 12 or so, marching lock-step to school with drums, bugles and flags.

“It was really quite colorful and powerful at first, and then you just had this overwhelming feeling of sadness, because at age 5 they were already marching like army drill teams,” said Green. “Which is why unification — it’s not just the material costs. The psychological challenge of knitting these two societies together — with that kind of regimentation but also a complete lack of a moral compass anymore in North Korea — is really daunting.”