N. Korea's Kim stokes a world crisis: Can he handle blowback?

As the world unravels North Korea's self-proclaimed hydrogen bomb test, the timing — ahead of ruler Kim Jong Un's birthday this week and a major government gathering in May — suggests a ruler trying to reassert his authority amid increased scrutiny and internal pressure.

Kim is believed to be his early 30s. When he succeeded his late father Kim Jong Il, who died in late 2011, longtime Korea experts wondered if a smooth succession was possible, and whether a young man with essentially little military or leadership experience could rise to power.

But in a few years, Kim — the seemingly comical despot with voluminous hair, a taste for cognac, movies and basketball (remember Dennis Rodman?) — is not necessarily a neophyte, if impetuous.

Kim has been vigorously reshuffling his innermost circle of leaders, in large part, to telegraph to the North Korean people and the international community that he's firmly in charge. For real.

KCNA | Reuters

North Korean leader Kim Jong Un watches a firing contest of the KPA artillery units at an undisclosed location in a photo released by North Korea's Korean Central News Agency in Pyongyang on Jan. 5, 2016.

In some cases, he has ordered the execution of leaders on allegations of treason — including some high-ranking officials who had served the country and his late father for decades. In the end, the declaration of a successful h-bomb test may largely be about sending a decisive message at a crucial time, a communication wrapped in fear.

Read More'Hydrogen' bomb test may backfire on North Korea

"He's giving his own people and senior leaders in the North Korean government a sign that he is dangerous and respected around the world," said Joshua Stanton, a blogger and long-time North Korea watcher who has advised Congress on North Korea sanctions legislation. "He wants everyone to be in awe of him."

Jung Yeon-Je | AFP | Getty Images

A South Korean soldier walks past a television screen showing a broadcast of North Korean leader Kim Jong-Un's New Year speech, at a railroad station in Seoul on Jan. 1, 2016.

One widely held assumption about North Korea is that its entire population of nearly 25 million people is zombie-like and moves in lockstep with Kim, as epitomized in mass rallies. While the country is indeed a sealed nation, North Korea is divided into a ruling elite class, with the remaining 99 percent scraping by on food rations, small private farms and pockets of free enterprise in North Korea's large black markets, which dot the country.

Of late, Kim has cracked down average North Korean citizens trying to flee. The country's borders have been sealed for decades, and getting caught with outside information or technology, often smuggled through China, is a punishable offense.

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So while the Cold War has dissolved, rogue North Korea, roughly the size of Pennsylvania, has steadied on. Inside its ruling class that includes top government officials, there's a massive organizational chart of leaders and deputy leaders. And it's from this bureaucratic, ruling machinery that Kim manages and demands loyalty.

The north has since managed an improbable three-generation lineage. And all three men have done so by instilling and using fear.

Two years ago, in December 2013, Kim ordered the execution of his uncle, Jang Song Thaek. At the time, Jang was one of North Korea's most powerful individuals among the ruling elite. Described by one Korea expert as a "prince maker" to CNBC, Jang's execution was largely about managing the power of North Korea's 1 percent, who enjoy privileges like access to imported luxury goods and can in some cases board commercial flights in and out of the country.

Jang had amassed one of the north's largest and most powerful group of state trading firms. And Jang's execution eliminated, arguably, the most influential senior party official remaining from Kim's father's era, according to a 2013-14 report from the Pentagon to Congress.

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Jang also pinpointed one of North Korea's growing weaknesses: lack of economic reform. While the ruling elite has achieved a degree of financial independence from the government, the 99 percent rely on black markets for rice, beer, clothing, school supplies and outside information. The markets can be lively, and transactions are done using cash including Chinese currency. Despite a food ration system, North Korea could not feed its own people without the black markets, according to experts and defectors.

"Most people are now involved in the black market," Yeon-mi Park, a North Korean defector, told CNBC in 2014. "If they don't go to the black market to do business, they cannot survive," she said. Park has since authored a book on her escape, "In Order to Live: A North Korean Girl's Journey to Freedom."

Last month, a top North Korean aide died in a car accident, according to the country's official news media, though there's speculation about that account of his disappearance.

Among Korea watchers, there's whispering about the probability of traffic accidents in a country with outdated roads and infrastructure. Basics like electricity are a luxury. Lower-floor apartment units are coveted as they reliably can be accessed by stairs. Elevators usually don't work.

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The young Kim, meanwhile, has been reshuffling the ruling elite, much more quickly than his late father — a red flag for some experts.

Kim's father Kim Jong Il stepped into the north's party machine in the 1960s and began purging select individuals. "Kim Jong Il had 30 years to clean the ranks before he became the leader," said Bruce Bennett, senior defense analyst at the Rand Corp.

And in a strategy move that could topple a "Game of Thrones" plot line, Kim Jong Il, when he was alive, limited his son's authority. "Kim Jong Il didn't want his son to do what he had done to his father," Bennett said.

In contrast, Kim Jong Un has orchestrated change and purges in only four years of rule. "That's got to be making a lot of people worried and angry as they watch what happens to their superiors," Bennett said. "That's got to be really scary for people in the government. You never know when you're going to be next," he said.

Another hydrogen bomb test?

KNS | AFP | Getty Images

Kim Jong-Un inspects the command of Korean People's Army Unit 534.

With the self-declared hydrogen bomb test, Kim "is probably trying to demonstrate that he is powerful, and that there really is no No. 2," Bennett added.

In addition to Kim's birthday, the leader faces increased pressure ahead of a top-level "party congress" in May. It's only the seventh such gathering in the nation's history, and the last one was held decades ago. "There's speculation he plans a major government reorganization," Bennett said.

As the White House and other Korea experts have disputed the north's claims of a hydrogen bomb test, there are other fresh concerns. Could Kim be under pressure to attempt a second h-bomb test and fan the possibility of a nuclear catastrophe?

What Kim doesn't want is news of an unsuccessful test filtering back to the north's ruling elite, and essentially undermining his authority. "If the test doesn't look like it worked, he may be under pressure to do another test to say, 'Hey, we really got into the hydrogen age,' " Bennett said.

Much focus now is on how China will react, as the fate of the two nations is inextricably linked. China provides North Korea with the lion's share of access to outside financial institutions, according to previous congressional testimony and U.N. documents.

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Infiltration of information and trading of goods make their way through the porous, 880-mile border between North Korea and China. And what China and neighboring nations such as Japan don't want is an abrupt collapse of North Korea and flood of refugees that would devastate the regional economies.

China has also consistently threatened to veto any North Korea-related resolution that includes a referral to the International Criminal Court. A landmark United Nations report in 2014 found wide-ranging human rights violations, and accused the regime of "crimes against humanity."

"The gravity, scale and nature of these violations reveal a state that does not have any parallel in the contemporary world," according to the U.N. report. The north responded with its own report, saying its citizens enjoy genuine human rights.

"If a resolution that takes on human rights has a provision that blocks North Korean assets, that could have more impact financially," said blogger Stanton, also an attorney. "It would delegitimize Kim Jong Un in the eyes of the regime."

Bottom line: Chinese leadership can't be happy.

Kim "must be facing some internal instability that he would do something to infuriate the Chinese," said Bennett of the Rand Corp. "He has got to be under some pressure," he said. "But we don't know if he's being cavalier, or just running scared."