At 9:22 p.m. on March 26, the ROK Navy corvette Cheonan sank in the Yellow Sea just south of the disputed Northern Limit Line near Baengnyeong Island after an explosion in the ship’s stern ripped it in two. Of the 104 South Korean sailors on board, 58 were rescued; 46 are dead or remain missing. Experts from the United States, the United Kingdom, Australia, and Sweden assisted in an internationally transparent investigation into the explosion, the results of which were announced on Thursday, May 20. South Korea has now publicly blamed the North for the attack, but North Korea still denies any involvement in the Cheonan’s sinking and accuses the South of deliberately souring relations.

Q1: Did North Korea sink the ROK naval vessel with a torpedo?

A1: According to the team of international investigators, “The evidence points overwhelmingly to the conclusion that the torpedo was fired by a North Korean submarine… There is no other plausible explanation.” During a final search of the seabed where the Cheonan sank, the propellers, a propulsion motor, and the steering section of a torpedo were discovered and later matched to a known North Korean torpedo model. The Korean script on these salvaged pieces also confirms its North Korean origin. Compounding this physical evidence is the fact that several submarines left a North Korean naval base in the Yellow Sea a few days prior to the attack and returned a few days following the sinking.

Q2: What has the United States done in response to the incident?

A2: President Obama sent condolences to the ROK president on the deaths of the 46 ROK sailors. The United States also cooperated with the salvage operation and the forensics of determining the cause of the sinking. Secretary of State Hillary Clinton, who will visit Seoul this week, has said, “The Republic of Korea can continue to count on the full support of the United States… Our support for South Korea’s defense is unequivocal.” The ROK government has indicated its intention to take the matter to the UN Security Council, and it can be expected that the United States will endorse this move as well.

Q3: Isn’t this style of attack typical of North Korea’s bluster and occasional provocations in the disputed West Sea area? Why is the attack on the Cheonan so significant?

A3: North and South Korean vessels have tangled before in the disputed West Sea area, with the last major provocation in November 2009 where an altercation resulted in the deaths of two North Koreans. (For a history of past provocations and altercations, see http://csis.org/files/publication/100525_North_Koreas_Provocations.pdf.) But the attack on the Cheonan constitutes an entirely different level of hostility. The last act of this magnitude involving losses of life occurred in November 1987 when North Korean terrorists blew up a South Korean airliner (KAL 858), killing 115 passengers and crew over the Andaman Sea. In terms of military provocations, it can be argued that the sinking of the Cheonan is the most significant attack on the ROK military since the Korean War, violating the 1953 armistice.

Q4: What was the North Korean motive for the attack?

A4: We can only posit theories as to why this would have been done:

§ The action could have been a disproportionate retaliation for a November 2009 clash in the West Sea that led to the loss of two North Korean lives;

§ The act could have been a form of coercive diplomacy trying to force the conservative and nonengagement-inclined ROK government into negotiations in which North Korea could extract aid and assistance;

§ The act could have been a form of “swaggering” to demonstrate to South Korea and to the region its recent efforts at enhancing its naval capabilities;

§ The act could be a manifestation of internal leadership turmoil in Pyongyang and the pursuit of a hard-line external policy. Dictatorships undergoing internal political turmoil generally manifest belligerent external behavior.

Q5: Will this incident impact efforts to restart the Six-Party Talks?

A5: Almost certainly. Quiet efforts by the United States and others to engage in preliminary discussions with the North Koreans to restart Six-Party Talks prior to the ship’s sinking have all been shut down as a result of this incident. The ROK government has made clear that it is not interested in returning to the Six-Party Talks until the conclusions of the investigation.

Q6: Now that North Korea has been found culpable for the sinking of the Cheonan, what courses of action are available?

A6: The responses outlined by President Lee on Monday range from military to political:

§ Nearly all inter-Korean trade will be severed, barring the Kaesong Industrial Complex;

§ Joint military exercises will serve as a show of reinforced U.S.-ROK capabilities, naval and otherwise, in the region;

§ North Korean merchant vessels will be blocked from using South Korean sea-lanes;

§ South Korea will also restart its “psychological warfare” campaign along the DMZ, through loudspeaker broadcasts and pamphlet distribution via balloons;

§ There will be efforts to seek UN Security Council authorization for further punitive actions against North Korea.

Q7: What is likely to happen if this issue goes to the UN Security Council? What will be China’s response?

A7: The South Korean government has indicated that it will seek tougher UN sanctions aimed at hurting the North Korean military. However, what China’s reaction will be is more uncertain since it has yet to articulate a definitive stance on the issue. The best we can hope for is that, as a voting member of the Security Council, China will not veto any resolution brought to the table.

China’s behavior thus far regarding the Cheonan has been clumsy, weak, and anachronistic. It has basically acted like North Korea’s defense lawyer in the public arena and tried to maintain the status quo on the Korean peninsula. The dilemma faced by Beijing is that provocative acts by the DPRK put pressure on China’s strategic objective of separating its relations with North and South Korea. Since normalization with Seoul in 1992, China is the only major power (with Russia) in the region that has diplomatic relations with both Koreas and the potential to effect positive change. Yet, Beijing has consistently chosen to delink the two, neither calling on the DPRK to reciprocate ROK engagement, nor heeding Seoul’s entreaties for Beijing to use its material leverage to help curb Pyongyang’s bellicosity. While most understand China’s dilemma, many see Beijing’s “muddle through” strategy as a disappointing symbol of its inability to play a leadership role in East Asia commensurate with its rise. This inability to make hard choices on the peninsula helps to explain the gap between China’s rhetoric of cooperation with other members of the Six-Party Talks and its actions on the ground.

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