He's been called part of the "Axis of Evil," but now that Kim Jong Il is dead it's possible that the instability created by his death might spell more danger for the West and South Korea.
Today, even as South Korea raised its military's alert level and North Korea tested short-range missiles off its eastern coast, the threat of North Korea without Kim is difficult to define.
The White House reacted early by assuring South Korean leader Lee Myung-bak the United States had his back if anything got out of hand, and the leaders agreed to stay in "close touch" over the following days as the inevitable power struggle for succession in the isolated nation progressed.
"Proximity matters," said Steven Weber, a professor of political science at the University of California Berkeley. "When you are living next door to an unstable, crazy neighbor, any change is unsettling."
Yet, experts say without being on the ground in North Korea it is impossible to know how the government is transitioning in Pyongyang or what risk it poses.
"It's comparable to Kreminology, the only difference is that we knew more about Russia," Weber said, referring to the analysis during the Cold War of internecine fights for power in the Soviet Union.
Joanna Spear, an associate professor of international affairs at George Washington University, says that the worst case scenario is that North Korea chooses to play out it's internal drama externally in an effort to unite the country in a time of turmoil.
"They are known for manufacturing crisis in order to present themselves to their people as protecting the nation against a bellicose West and South Korea," she says.
Kim Jong Il's youngest son, Kim Jong Un was named the heir apparent last year, but Richard Bush, the director of the Center for Northeast Asian Policy Studies says Kim Jong Un won't necessarily be accepted by all factions to lead the country.
Kim Jong Il had almost 20 years to gain control before the death of his father and founder of the so-called Democratic Republic of Korea, Kim Il-Sung. However, Kim Jong Un has had less than three years to learn the ropes, which left little time for the heir to gain support from the military, the Korean Worker's Party, security agencies and the government administration.
"As the elder Kim's health seemed to improve, the pace of the transition slowed down, because he did not wish to deplete his own power as he positioned his son," Bush says. "His sudden death from the heart attack throws that into chaos."
Bush adds the most likely scenario to play out in North Korea is the formation of a collective leadership, which would rule in the name of the Kim family—essentially a regency. Bush says that these types of ruling groups are vulnerable to instability.
"It is not impossible that different factions in the leadership will fight amongst themselves over power and resources," Bush says.
Bush and others like Peter Hayes who have worked with the Nautilus Institute to implement creative development programs on the ground in North Korea believe there is always the chance that a regime change could gradually lead to warmer relations with the isolated country.
Kim Jong Un reportedly attended school in Switzerland for a time during his early teens and is said to have both English and German language skills.
"He is a cosmopolitan young man. He could surprise us," Hayes says. "I think it's unlikely that North Korea engages fully with the West, but it's low-lying fruit waiting to be plucked by a new administration."
What is extremely unlikely, experts say, however, is an uprising similar to those that took hold in Libya, Egypt, Syria and Tunisia this year.