The United States and South Korea are facing new and increasingly dangerous dynamics on the Korean Peninsula. The situation in North Korea underwent an enormous qualitative change over the past three months that heightens the urgency of a potential crisis for the North and could even signal the regime's eventual undoing.

North Korean Supreme Leader Kim Jung-un's decision to purge and execute his uncle and quasi-regent Jang Song-thaek and, more significantly, the manner in which he chose to do so have driven dangerous cracks throughout the edifice of North Korean power. The power structure is now more dangerous to its occupants than before, and their behavior is likely to be more threatening to outsiders than in the past. This is because the supreme leader has chosen to demonstrate to his own people the shortcomings of his rule and its system, diminishing his and his regime's prestige and authority in the vain pursuit of consolidated power.