The execution of one of the isolated country's highest-ranking officials is raising questions about its stability. NewsHour correspondent Kwame Holman begins our report.

　　KWAME HOLMAN: Until very recently, Jang Song Thaek was considered the second-most powerful figure in theDemocratic People's Republic of Korea. But on state TV today, his remarkable demise was made official.

　　NEWS ANCHOR (through interpreter): The special military tribunal of the Ministry of State Security ofNorth Korea condemned Jang Song Thaek as a wicked political careerist, trickster and traitor, in the name of the revolution, and the people ruled that he would be sentenced to death. The decision was immediately executed.

　　KWAME HOLMAN: Married to the aunt of leader Kim Jong-un, Jang ascended the country's ranks rapidly following the stroke of Kim's father, Kim Jong Il, in 2008. And he rose further still following Kim's death in 2011.

　　Though not a career military man, he was made a four-star general and was fond of appearing in his white military uniform at state events. He played a key role in shaping economic policy and was considered the architect of the country's joint ventures with neighboring China.

　　However, in Beijing today, a spokesman was tight-lipped regarding the news of his death.

　　HONG LEI, Chinese Foreign Ministry (through interpreter): This is North Korea's own internal affair. As a neighboring country, we hope for North Korea to maintain stability, economic development, and a happy livelihood for its people.

　　KWAME HOLMAN: As with word of his execution, Jang's removal from office was broadcast on state TV earlier this week, as the 67-year-old was taken from a Central Committee meeting by uniformed guards. He was accused of a litany of crimes, from gambling away $6.3 million, to womanizing, to attempting to overthrow theleadership, to not showing proper enthusiasm for his nephew's achievements.

　　In Seoul, South Korea, the high-level purge has put officials on guard.

　　RYOO KIHL-JAE, South Korean Unification Minister (through interpreter): Generally, in the past, we have seen that efforts to crack down on internal insecurities then lead to external provocations. We are paying close attention to such a possibility this time as well.

　　KWAME HOLMAN: Next week, the country marks the two-year anniversary of Kim Jong Il's death.