The South Korean government has concluded that a North Korean torpedo caused the March 26 sinking of a South Korean naval ship, killing 46 sailors. South Korea and the U.S. will now advocate a strong response to North Korean complicity in the sinking of the Cheonan but stop short of advocating a military retaliatory attack. Instead, Seoul will curtail -- if not sever -- economic engagement with the North, review its military posture, and augment naval forces and sensors along the Northern Limit Line. The Lee administration, in conjunction with Washington and Tokyo, will want to take the issue to the U.N. Security Council to condemn North Korea’s heinous act and impose additional punitive measures.

It is absolutely critical for the Obama administration to fully support our South Korean ally during its time of tragedy and crisis. There must be no daylight between Washington and Seoul nor any perceived differences in the bilateral response to Pyongyang’s blatant act of aggression. Washington should fully support South Korean efforts for a new U.N. Security Council resolution.

China remains weak link in international response

The biggest obstacle will be Chinese reluctance to respond resolutely to such a blatant act of aggression. China will react with its customary call for caution and restraint in punishing North Korea. However, South Korea and the U.S. should not be deterred from pressing Beijing hard since China can sometimes be moved beyond its comfort zone, albeit grudgingly and not as far as Washington would want. It acquiesced to U.S. pressure to impose sanctions on North Korea after its 2006 and 2009 nuclear tests. A blatant North Korean provocation such as the sinking of the Cheonan could provide South Korea and the U.S. with sufficient leverage to get Beijing to agree to some stronger measures against North Korea.

Impact on six-party talks

The six-party talks, already on terminal life support, may flatline as a result of the Cheonan sinking. South Korean officials have commented privately that six-party talks would likely be delayed six to 12 months since it would be seen as inappropriate to negotiate with North Korea when they have the blood of the Cheonan sailors on their hands. Even when inter-Korea discussions resume, Seoul will be far less amenable to providing benefits to Pyongyang.

Expect more North Korean provocations

As if the Cheonan attack was not bad enough, Seoul will be nervously waiting for the other shoe to drop. It can be expected that North Korea will react strongly to any international efforts to punish it for the Cheonan attack. It is also likely that the Cheonan sinking is not a singular event but rather the beginning of a North Korean campaign to raise tensions. Pyongyang could even be looking for a strong international response to the Cheonan sinking in order to justify additional belligerent behavior. If that is the case, then North Korea will engage in additional provocative behavior, particularly in the run-up to Seoul’s hosting of the G-20 summit in November.

Bruce Klingner is senior research fellow for Northeast Asia in the Asian Studies Center at The Heritage Foundation.