North Korea’s state television Korean Central News Agency made an official announcement that North Korean leader Kim Jong Il died at 8:30am on December 17. The announcement made two days after his death reported that he had died of a massive heart attack caused by stress and overwork while he was on a train for a field tour outside Pyongyang. He was 69 years old. Kim Jong Il suffered a stroke in 2008 and since then has been struggling with feeble health. In late 2010, he anointed his youngest son Kim Jong Eun as his successor. North Korea’s state media said the funeral will be held on December 29, and the mourning period will last for 10 days.

Q1: What is the significance of this event?

A1: This is a watershed moment. Any expert would have told you that the most likely scenario for a collapse of the North Korean regime would be the sudden death of the North Korean leader. We are now in that scenario.

Q2: What will the United States do?

A2: Watch, wait, and prepare. The United States and the Republic of Korea (ROK) have developed military plans for contingencies involving North Korean instability. The first step would be to raise Defcon status. No military actions are warranted at the moment other than to watch and ensure stability on the peninsula and protection of the United States and the Republic of Korea.

Q3: What about China?

A3: China is the only country that has eyes inside of North Korea. The United States and the Republic of Korea have been appealing to China to engage in a dialogue about possible instability in the North since the stroke of Kim Jong Il in 2008. Beijing has been reluctant, but now it has little choice in the matter. Washington, Seoul, and Beijing must stay on the same page.

Q4: Will the youngest son be able to lead North Korea?

A4: It is very hard to say at the moment. Kim Jong Il had 14 years to prepare to take over for his father Kim Il Sung when he died in 1994. Kim Jong Eun has had barely three years. He has had little preparation in cultivating his own followers. He has no new ideology to associate with in his rise to power. I could not think of less ideal conditions—in a North Korean context—under which he could be given the reins of power.

Q5: What about U.S.-DPRK relations and the reports last week that we were headed back to nuclear negotiations?

A5: Everything is on hold now. Last week’s talks about food aid and the possibility this week of another U.S.-DPRK bilateral meeting on the nuclear issue are probably all “OBE”—overtaken by events. These bits of diplomacy constituted small bites at the apple. We are now talking about the whole apple.

Victor D. Cha holds the Korea Chair at the Center for Strategic and International Studies (CSIS) in Washington, D.C.