Seoul, South Korea – It is becoming increasingly obvious that a North Korean torpedo caused the March 26th sinking of a South Korean naval ship. The Cheonan, a 1200 ton corvette, was severed cleanly in half, a characteristic of torpedo attack rather than a naval mine. Seoul has already ruled out an internal explosion, running aground, or other accident as the cause.

My discussions with government officials in Seoul this week revealed uncharacteristic reticence and nervousness. South Korea is now like a CSI investigator who, upon seeing a dead body with a bullet hole in the forehead refuses to rule out a heart attack as the cause of death since the only suspect in the room with a pistol is a vicious gangland boss. Better to engage in a lengthy investigation, both to gather irrefutable evidence and to delay the inevitable day of reckoning.

Everything in South Korea is on hold pending the outcome of the investigation. Government contacts are reluctant to be drawn into discussions of hypothetical policy responses. Some newspapers, public organizations, and legislators have called for a strong response but have yet to gain traction with the populace whose mood is predominantly one of mourning.

It appears the public is angry, but not angry enough to advocate military strikes against North Korea that could escalate into an unpredictable all-out conflict. At this point, it appears unlikely for Seoul to contemplate a military attack. There is repeated precedent for both South Korea and the US not responding militarily to previous North Korean attacks, even when they resulted in loss of life.

All of that could change, however, upon the final conclusion of the ponderous investigation. Ironically, Seoul appears concerned by both potential outcomes, namely either too much or too little evidence. A clear verdict of North Korea’s finger on the trigger could inflame the public to demand a stronger military response than either Seoul or Washington would be comfortable with.

Conversely, strong suspicion but a lack of irrefutable evidence will constrain Seoul’s policy options. South Korea will contemplate both unilateral actions, including punitive economic and diplomatic measures, as well as taking the issue to the UN Security Council for multilateral response. In the latter case, Seoul would face stiff opposition from China and Russia, which have obstructed previous attempts to punish Pyongyang for violating UN resolutions.

If South Korea is reluctant to attack, it would be impossible for the US to be “more Korean than the Koreans” by advocating stronger measures. But the Obama administration should consult closely with the South Koreans and support whatever action they are comfortable taking. This should include pressing the Chinese and Russians to relent in favor of tougher international sanctions, and taking unilateral punitive action that complements the South Korean approach.

Some South Koreans were sharply critical of Secretary of State Hillary Clinton’s recent comment that she hoped there would be “no action or miscalculation that could provoke a response that might lead to conflict [and] the way to resolve the outstanding differences among [the Koreas was] to return to the six-party talks framework as soon as possible.”

This value-neutral, even-handed approach to North and South Korea when Seoul was clearly the aggrieved party resurrected memories of Secretary of State Warren Christopher’s insulting 1996 comment calling upon both Koreas to show restraint after North Korean special forces killed 10 South Korea citizens.

All told, the Cheonan crisis is taking place at a time of very solid bilateral relations between the US and South Korea. The strength of this alliance contrasts sharply with Washington’s troubled relationship with its Japanese ally. A united US-Korea response to North Korean provocation underscores the value of alliance with the U.S.

One wonders how the US-Japanese alliance would respond today to a similar crisis.