Jang was executed, reportedly by machine-gun firing squad, after being convicted of treason.
At 67, Jang had achieved much more than an ordinary bureaucrat, who dutifully towed the regime line. He had the vision and ambition to pinpoint the North's growing weakness—lack of economic reform. Jang tapped into that vulnerability to the regime's advantage, and according to charges filed against him, ultimately for his own benefit.
What was it about Jang that bred such loyalty and strong feelings?
Based on previously aired footage of military parades and children dancing methodically, it can be difficult to imagine North Koreans with emotional depth. But inside the North, allegiances beyond those to the "Dear Leader" have been maturing for years.
Again life in the North, especially among the elite, is dynamic. When the former North Korean leader Kim Jon Il died two years ago, there was a power shift. And his wife's brother Jang was right there to offer solace—and a position in one of his state trading firms—to those who had fallen out of favor. "Jang was good at rehabilitating them," Park said. Inside North Korea and during his travels to China, Jang proved a master at cultivating relationships and loyalties.
Amiable and politically savvy, Jang parlayed his encyclopedic knowledge of the North's power infrastructure to his advantage. These skills combined helped him ascend the ranks of North Korea's elite. "He gave rise to this phenomenon of monetization of political relationships," said Park.
The rare public nature of Jang's purge—televised nationally—shows how widespread and threatening his influence had become. On Monday, North Korea erased Jang from its Web archives.
In the end, based on charges against him, Jang may have shifted his chief priority to amassing his own wealth over catering to the Kim family, as the indictment suggests.
An alarming charge against Jang emerged.
According to the indictment, "Not only was Jang amassing power in the military, party and indirectly in the state, but he was plotting an outright coup," Stephan Haggard wrote in a recent blog post on the Peterson Institute for International Economics website.
"Even more interesting is how he (Jang) was expected to do it: he hoped to exploit a deterioration in the economy to ultimately become premier," Haggard wrote.
(Read more: Inside North Korea's not so isolated, free-enterprise economy)