As Kim Jong Il dies, what’s next for North Korea?

>>> good evening. it's more than just the death of a dictator. kim jong -il of north korea is gone. we believe his son is taking over , but it's the fact that for example we don't really know for sure how old his son is or who is running a big dangerous nuclear-armed and isolated country that has ushered in a new period of uncertainty. some background here briefly beforehand. there are 24 million people in north korea , most of them very poor. it is believed malnutrition affects one in three children. it is further believed a famine a few years back killed a million people. the north korea military is the world's fifth largest. of course we fought a war over korea and have well over 20,000 troops there. they are now believed to be in possession of nuclear, biological and chemical weapons by the ton. it's against that backdrop that we are not just covering the death of an aging and sick dictator. we now look at what happens next as well. we begin tonight with our chief foreign affairs correspondent andrea mitchell . andrea, good evening.

>> reporter: good evening. the sudden death of kim jong -il known to his people as dear leader creates hunl uncertainties. for now pyongyang's residents don't know who will be in charge of the nuclear weapons . on state tv, images of sobbing north koreans in declining health since a stroke in 2008 north korea said kim died suddenly of a heart attack two days after this picture was taken. emotions seemed to grip the anchor on state television who broke the news. named as his successor kim 's untested youngest son kim jong -un. president obama made a midnight call to reassure south korea 's president. the u.s. with more than 28,000 troops on the peninsula will stand with the south.

>> we reiterate our hope for improved relations with the people of north korea and remain deeply concerned about their well-being.

>> reporter: kim jong -il's reign of terror lasted 17 years. menacing his neighbors with nuclear weapons , holding his own people hostage with prison camps and starvation. two years ago it took a former president to free two american journalists who strayed across the border from china. kim did not look the part. so short he wore elevated heels, adding inches more with bouffant hair, favoring olive drab jumpsuits and oversized sunglasses. drinking cognac and fine wine while millions of his people starved. kim traveled with a harem of women some called his joy brigade in a luxurious railroad car . he collected hollywood films and videos of the chicago bulls . when secretary of state madeline albright visited in 2007 she discussed normalizing relations with the u.s. she gave him a basketball signed by michael jordan . kim staged a military pageant for her benefit. she said she had no illusions.

>> i can assure you these glasses i have on are not rose-colored.

>> reporter: kim had years to emulate the cult of personality created by his father, the nation's founder, kim il -sung. now his youngest son takes over. does he have the skill to control the military or will he be a figurehead? almost nothing is known about him. he's believed to be 28 years old, was educated briefly in switzerland. unlike his father has had little time to prepare for his new role.

>> one of the big questions as we look down the road is whether this is going to be a successful leadership transition or whether the regime will simply not be able to hold it together.

>> reporter: this is a regime that has confounded generations of american leaders. while u.s. intelligence repeatedly fails to anticipate north korea 's nuclear progress and its missile test.

>> they are going to send signals that they are tough and don't mess with us. so i think i would expect some more. hopefully they are not going to do it in a way that provokes south korea to respond in kind.

>> reporter: kim 's death comes on the very day that u.s. diplomats in china were to meet with north korean counterparts on a new food aid for disargumentment agreement that is now on permanent hold.

>> what do you look for anywhere from 24 hours to two weeks?

>> reporter: or even longer. the real worry is loose nukes. just who's in charge of those weapons? and the fear of provocative military action by a young leader trying to prove himself or the military trying to show its muscle. and the u.s. is urging south korea , of course, to remain calm but there is no love lost for the so-called dear leader . tonight john mccain said, i can only express satisfaction, quote, that the dear leader is joining the likes of gadhafi, bin laden , hitler and stalin in a warm corner of hell.

>> a lot of people are making fun of the pictures of mourners because some of them look aware of the camera and perhaps coerced to some eyes.

>> reporter: exactly.

>> andrea mitchell in our washington bureau starting us off tonight.