North Korean leader Kim Jong Il's son Kim Jong Un...

North Korean leader Kim Jong Il's son Kim Jong Un attends a massive military parade marking the 65th anniversary of the ruling Workers' Party in Pyongyang, North Korea. North Korea's news agency reported Monday, Dec. 19, 2011 that Kim Jong Il had died on Saturday, Dec. 17 after having a heart attack on a train. On Monday the news agency dubbed Kim Jong Un a "great successor" as the country rallied around him. (Oct. 10, 2010) Credit: AP

With North Korea appearing to be deeply mourning its "Dear Leader," Kim Jong Il, the Pyongyang government tried to reassure its people yesterday with a message about his son, the "Great Successor."

"Under the leadership of Kim Jong Un," North Korea's state-run media said, "we should turn our sorrow into strength."

North Korea has had just two leaders in 63 years: the elder Kim, who died Saturday of a heart attack, according to state media, and his father, Kim Il Sung.

Now, the reclusive government says, Kim Jong Un, believed to be in his late 20s, will continue the dynasty and grapple with the challenge of holding the deeply impoverished, nuclear-armed country together.

Kim Jong Un will be one of the world's most unknown -- and significant -- power-holders, potentially capable of reforming the country, maintaining it, or letting it slip into chaos.

The youngest of Kim Jong Il's three sons, he has neither the resume nor the experience to control the country in the rigid manner of his father and grandfather, experts say.

For security experts in Seoul and Washington, the younger Kim's rise turns North Korea from a truculent state into a volatile one, far likelier to threaten its neighbors or show signs of civil unrest.

Until late last year, most North Koreans had never seen Kim Jong Un's adult photograph. Pyongyang's propaganda office had begun taking cautious steps to build the successor's personality cult -- but the process was designed to last years, not months.

Analysts who have studied North Korea's second attempted power transfer fear several scenarios, including a revolt by the military or a fight for power among older party members, who view Kim Jong Un as a vulnerable target, too young to have his own allies and loyalists.

"This is really the worst possible nightmare for the North Korean state -- this sudden death, and for the son to be taking over," said Victor Cha, former White House director of Asian affairs under President George W. Bush. "This could collapse before our eyes."

Before Kim Jong Il's death, experts and government officials in Seoul and Washington agreed on at least one major point about the North Korean father-to-son power transfer: The longer Kim Jong Il lived, the better its chances.

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Gabby Petito lawsuit ... Snow cleanup laws ... Teen pregnancy ... Taping hands ... Plays of the week ... What's up on LI ... Get the latest news and more great videos at NewsdayTV

Get the latest news and more great videos at NewsdayTV Credit: Newsday

Gabby Petito lawsuit ... Snow cleanup laws ... Teen pregnancy ... Taping hands ... Plays of the week ... What's up on LI ... Get the latest news and more great videos at NewsdayTV

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME