Last week's sudden execution of North Korea's second most powerful official has led to conflicting interpretations. Jang Song-thaek was Kim Jong-un's uncle by marriage and North Korea's closest friend of China. The public accusation that he was organizing the overthrow of the Kim dynasty includes the words, "if the living of the people and service personnel further deteriorate in the future." That language is an unusual admission that the country is not doing well. Is 30-year-old leader Kim Jong-un showing who's really in charge or revealing weakness? What are the consequences for other top cadres, relations with China and the US? Professor David Kang is Director of the Korean Studies Institute at the University of Southern California.