Last Sunday, a crowd of young North Koreans marched through a square in their capital city. They brandished red flags and called for a higher standard of living. But they also carried placards glorifying leader Kim Jong Il, and only a day earlier, they had attended an ideology seminar at which they pledged their loyalty to the current social order.

As leaders in other authoritarian countries fall, flee or fight to stay in power, the Kim family has retained its unequivocal control, including taking quiet steps to broaden the power of heir apparent Kim Jong Eun. Though some experts note public disenchantment over food shortages and inflation, the Kims — backed by the military, deified by propagandists, enriched by what little money flows into the country — still exercise muscular authority in the places that matter.

“Let’s unite around the General Kim with loud steps,” read a front-page editorial in last week’s state-run newspaper, in an apparent reference to Kim Jong Eun. “Victory is ours.”

Analysts and foreign government officials have recently noted numerous signs that Pyongyang is redoubling its efforts to ensure a successful father-to-son power transfer. South Korean Foreign Minister Kim Sung-hwan said Thursday that North Korea is strengthening its ban on outside media information that could undermine domestic propaganda. At a U.S. Senate Foreign Relations Committee hearing Tuesday, Sen. James E. Risch (R-Idaho) asked diplomats for an explanation of North Korea’s “non-understandable” behavior, including last year’s military strikes on a South Korean warship and island.

“Everything that the North Korean government does — domestically and internationally — is aimed at one goal,” responded Stephen Bosworth, the top U.S. official for North Korean policy. “And that is perpetuation of the regime.”

“I’d be more particular,” said Kurt M. Campbell, the State Department’s top East Asia official. “It’s the survival of the family.”

According to high-level North Korean defector Kim Kwang Jin, a former operative in Kim Jong Il’s financial network, North Korea is trying to boost Kim Jong Eun’s image by linking him to the country’s founder, Kim Il Sung. Around the time that Kim Il Sung died, in 1994, North Korea’s economy collapsed — although largely because of reductions in Chinese and Soviet aid. Even so, Kim Il Sung remains a “God-like figure” for North Koreans, Kim Kwang Jin said.

So North Korea has surrounded the next-generation leader, thought to be 28 years old, with a network of Kim Il Sung’s cousins (by marriage) and loyalists. It has created a Kim Jong Eun propaganda song by revising the lyrics to an old tune that North Koreans associate with the Kim Il Sung era. According to Kim Kwang Jin, the effort extends to physical appearance as well. Kim Jong Eun wears a jacket similar to the one Kim Il Sung wore as a young man, and his haircut — a jet-black mushroom cap — bears a resemblance to Kim Il Sung’s in his early years.

“It is very hard for them to find the legitimacy for another succession,” said Kim Kwang Jin, who recently released a report on the succession. “So they are clinging to the grandfather’s legitimacy.”

In late September, North Korea unveiled the heir apparent at a landmark party conference, giving him several high-profile positions, including vice chairmanship of the Central Military Commission. Given the opacity and complexity of North Korea’s leadership structure, however, outside analysts were not certain where to place Kim Jong Eun in the hierarchy. Was he already powerful? Or was he merely on the verge of becoming powerful?

North Korea, according to Kim Kwang Jin, has already moved to ensure that Kim Jong Eun will inherit unquestioned authority when his ailing father dies, by revising the Workers’ Party charter at September’s conference.

The revisions, which became public in January, include a declaration that the head of the Workers’ Party also heads the Central Military Commission.

And its significance, Kim said, is hidden by its inversion. “Really,” he said, “it’s that the head of the Central Military Commission becomes head of the party. And because Kim Jong Eun is already number two in the CMC, he automatically becomes number one when his father dies. Then he automatically takes over the country.”

For foreign intelligence organizations and outside experts, North Korea remains perhaps the world’s most challenging subject. It reveals itself in riddles and thrives on misdirection. After a belligerent 2010, it launched a charm offensive with a peace-preaching New Year’s Day pledge. Then its military officials walked away from talks with their South Korean counterparts, leaving the Seoul government bracing for another wave of provocations.

The Kim family, meanwhile, is pushing for closer ties with China, according to a Chinese document obtained by North Korea expert Lee Yong-hwa, of Kansai University in Osaka, Japan. The document, Lee said, indicates that Pyongyang and Beijing have discussed a meeting in March or April between Kim Jong Eun and Xi Jinping, who is slated to become China’s next president. Kim Jong Eun would travel to China for the meeting.

“China is going to do PR for North Korea, to say that a Kim Jong Eun regime is not an unstable one,” Lee said in a phone interview. “North Korea has economic problems, and there is dissatisfaction toward hereditary succession. So China feels it needs to give underlying support.”

Special correspondent Akiko Yamamoto contributed to this report.