It was revealed last week that Thae Yong Ho, deputy ambassador of the North Korean Embassy in the United Kingdom, has defected. He is the most senior North Korean diplomatic official to ever defect from the North to the South. Thae is the most recent in a number of defections, prompting speculation that Pyongyang is growing more unstable. The key word here is "speculation." While there are indications of instability and uncertainty, Kim Jung Un remains North Korea's supreme leader and there is no viable challenge to his authority.

Thae has an impressive pedigree. His father was a general who fought with Kim Il Sung, founder of the North Korean state and the grandfather of Kim Jung Un. Thae went to high school in China and speaks Chinese and English along with his native tongue. That fluency made him a very visible figure in London, where he was a glib defender of the Pyongyang government and its policies. His wife was equally well connected: Her father was also a close associate of the senior Kim. His children attended British schools; one received a university degree and the other went to a London high school.

The entire family defected to South Korea. After several days of silence, South Korea's Unification Ministry announced that Thae left because he was "tired of Kim Jong Un's regime." The North responded through its KCNA news agency by denouncing Thae as "human scum" and a "criminal" who had been under investigation for "intentionally leaking secrets, embezzling state property" and a "sex offense."