How is Kim Jong-un trying to make his mark?

North Korea leader Kim Jong-un – to all appearances – may never have seemed so powerful.

Mr. Kim has recently carried out a series of executions and purges of suspected enemies, and North Korea’s nuclear program appears much farther along than observers would have imagined even a year ago. Those are the two main data points from outside the shadowy and isolated nation. 

Recently, for example, Kim, now quite portly, was seen touring a gleaming new airport with his wife, Ri Sol-ju, and appearing proud and contented in photographs distributed by Pyongyang's Korean Central News Agency. He visited shops that will sell luxury goods not readily available elsewhere in the North.

The KCNA report did omit an unpleasant detail: the architect of the airport, Ma Won-chun, missing from the shots, is believed to have been executed, according to NK News, a Seoul-based website that closely tracks North Korea.

Kim was reportedly upset that the airport design team "failed to bear in mind the party’s idea of architectural beauty that is the life and soul and core in architecture to preserve the character and national identity,” as NK News detailed from contacts inside the North, but which can't be confirmed. 

The execution of an architect may be a minor event in the current purges that Kim relies on for his own and North Korea's survival. In November 2013 Kim executed his powerful uncle-in-law and one-time mentor, a man who most importantly controlled trade with China. 

Yet the show of power as seen in propaganda film and video, as well as Kim’s ability to order executions, may mask serious problems according to views from a variety of analysts and diplomats, some of whom have spent time in the North. They say that the young heir to the dynasty founded by his grandfather, Kim Il-sung, suffers from an insecurity complex and does not trust even his closest aides.

Masking insecurity?

The purges and executions highlight the shaky ground Kim is on as he takes control of a nation, analysts say, without either the authority or charisma of his father or grandfather.

Far from being "a sign of strength," says Victor Cha, who served on the National Security Council during the presidency of George W. Bush, the purges and executions "are symptomatic of significant churn inside of the system."

A key reason Asian analysts continue to watch Kim closely is the evident success of his nuclear program.

As the centerpiece of Kim's drive to impress subordinates and intimidate South Korea and Pyongyang's two major enemies, the US and Japan, North Korea's nuclear program has never been so important as now as a point of pride and power. 

"Kim Jong-un regards nuclear power and missile forces as the core of his armed forces," says Cheong Seong-chung, director of unification strategy studies at the Sejong Institute, a leading think tank here. "North Korea isn't able to maintain a great air force compared to South Korea but has the missiles and artillery to counter the South."

Reports given to American officials by Chinese intelligence suggest that the North may now have as many as 20 nuclear devices. It is also at work on three significant missile systems.

No miniaturized nuke, so far

While North Korea's short-range Scud missiles threaten all South Korea and portions of Japan, its mid-range Rodongs have the potential to deliver warheads anywhere in northeast Asia. Conceivably, some day, its long-range Taepodong could reach the US. 

At present, scientists and engineers in the North have not figured out how to fix a miniaturized nuclear device on a Rodong. That is now the quest driving Kim Jong-un to order and often witness missile tests. With that capability, North Korea holds a club that it can wield over the entire region – though not yet the US.

"He's at the point where the 50-year quest is reaching fruition," says Bruce Klinger, a former CIA analyst, now senior research fellow for Northeast Asia at the Heritage Foundation in Washington. "The best estimate is they've got 10 to 16 nuclear devices."

North Korea has conducted three underground nuclear tests, most recently in February 2013, and is presumably preparing for a fourth – despite warnings from China, its only real ally, the source of half its food, and most of its fuel.

The drive for nuclear-missile prowess parallels tumultuous shifts among top aides, most of whom rose up the ranks before his father, Kim Jong-il, died nearly four years ago. Most recently, Kim sought to affirm his authority by the execution of Gen. Hyon Yong-chol, minister of the people's armed forces, believed by South Korea's National Intelligence Service to have been executed by anti-aircraft gun after attending a security summit in Moscow.

General Hyon was photographed dozing while Kim was making a speech, but Mr. Cheong at the Sejong Institute says his real offense was to have remarked to North Korean officials with him in Moscow that Kim was "young" and "inefficient in politics." That remark, Cheong surmises, confirmed the view that Hyon represented a hard-line military view in conflict with the political leadership that Kim has emphasized through the ruling Workers' Party.

Public humiliation

Hyon's execution was the latest in a series that included, most dramatically, the public humiliation and then the killing of his uncle-in-law, Jang Song Thaek, in December 2013. Mr. Jang, married to Kim Jong-il's younger sister, Kim Kyong-hui, was often described as "regent," the country's second most powerful man. His downfall indicated Kim's desire to suppress "factionalism" tearing the system apart.

Mr. Cha, now a professor at Georgetown, sees the spate of missile tests as serving "a political purpose" even if "foremost" they "advance their weapons technology."

Choi Jin-wook, president of the Korea Institute of National Unification, agrees. "He is very serious about nukes and their delivery system," says Mr. Choi. "He thinks it is the most important to his survival. [The] purge is for him to show off his power. He wants to say that I am in charge here by purging his close staffs."

But how does purging dissidents – or mere recalcitrants – relate to nukes and missiles?

In the "politics of terrorism," says Kim Tae-woo, a former senior defense official, now a professor at Dongkuk University, "every military officer and high-ranking party cadre freezes in fear and tries to show maximum loyalty."

Kim may appear "more committed than his father to the whole nuclear program," he says, but actually "is far weaker than his father and grandfather."