SEOUL -- The U.S. news media are filled with reports about what is happening in North Korea. But perhaps readers and viewers should be aware that nobody in the U.S. media -- or government, for that matter -- really knows much about what is happening in North Korea.


The outside world continued waiting Tuesday for some indication from the renegade Communist state about who will succeed the late dictator Kim Il-sung. At issue is North Korea's clandestine program to develop nuclear weapons. And as always, veteran Pyongyang-watchers were scrambling for information from a nation that has always done its best to seal itself off from the rest of the world.


"What we know about that country," a U.S. expert said, "is incomplete and unreliable. Our sources of information are erratic and unreliable. We probably know less about North Korea than about any other serious foreign-policy concern in the world."


Since very few North Koreans ever leave the country, and few foreigners are allowed in, most normal routes of information flow do not exist.


Instead, the outside world relies on various forms of spying, both high-tech and low; on reports from a handful of foreign diplomats and travelers in the country; on a thin flow of defectors who manage to escape the police state; and on whatever information North Korea chooses to provide through radio and television broadcasts.


North Korean broadcasting is the most common source of information, experts say, but it is one of the least reliable. Since North Korea knows the outside world is listening in, South Korean Foreign Minister Han Sung-joo has noted, "there is a lot of skewed information" on its broadcasts. Moreover, the news that is released over the radio and television from Pyongyang comes only when Pyongyang wants to release it. This week, for example, the North Korean broadcasts have carried several reports suggesting that Kim Il-sung's son, Kim Jong-il, is likely to ascend to power, marking the first time any Communist state has had a hereditary succession. Many analysts here and in the West say they think these reports are accurate. On the other hand, since Kim Jong-il is believed by these analysts to control the state broadcasting service, nobody can be sure the news is reliable.


North Korean radio broadcasts each day both in Korean, for domestic and South Korean consumption, and in English, for the rest of the world. Those who monitor it say the content is generally identical in both languages -- for the most part, highly contentious propaganda about the virtues of North Korea and the evils of the non-Communist world.


To try to verify the varied information available from the North Korean media, outside analysts routinely talk to the handful of foreigners living in North Korea -- ambassadors from about a dozen countries, a few journalists from Russia and China, and some workers from international aid agencies. A small trickle of travelers also gets into North Korea each year.


But these foreigners rarely get a full look at North Korean society. They are restricted mainly to certain neighborhoods of Pyongyang, the showcase capital city, and three designated tourist sites. Generally, when foreigners have reason to travel out of Pyongyang, the government puts them in a car or train leaving the city after nightfall, so they pass through the countryside in darkness.


A very small number of North Koreans -- fewer than 10 people a year, South Korea says -- manage to flee the tightly guarded state and take asylum in the South.


The defectors tell amazing tales about depravity, ruthlessness and corruption in Pyongyang's ruling clique. Most of the stories now being floated in the Western press about drinking and womanizing by Kim Jong-il, the heir apparent, come from these defectors.