The South Korean government has released its report on the sinking of the Cheonan, the ship that went down in March in the Yellow Sea near the maritime border with North Korea. Not surprisingly, Seoul has fingered Pyongyang as the culprit. The evidence is rather strong.

First, the South Koreans have produced a fragment from a torpedo propeller. Second, there’s Korean lettering that matches the font used in another North Korean torpedo the South Koreans have. Third, the South Koreans have matched traces of propellant to an earlier North Korean torpedo.

There are some reports of other possible culprits, including friendly fire from either South Korea or the United States. While such speculation is interesting, it seems rather far-fetched. In this age of wiklleaks, it’s hard to imagine a cover-up of such friendly fire succeeding. And the evidence implicating other actors is circumstantial to say the least.

More germane is the backstory that Mike Chinoy provides over at Forbes. When South Korean president Lee Myung Bak took office, he backtracked on his predecessor’s pledge to work with North Korea to build confidence around the disputed maritime boundary.

The North was infuriated by what it saw as a deliberate belittling of accords signed by its all-powerful leader–what one western analyst described as “sticking a finger in Kim Jong Il’s eye.” So Pyongyang responded in a predictably belligerent fashion–by ratcheting up tensions in the disputed waters.

Fortunately, no one is calling for military retaliation against North Korea. Even the Heritage Foundation is going only so far as to recommend an economic cut-off, further isolation of North Korea, and a clear condemnation in the Security Council.

Other than express legitimate outrage, what would these stepped-up containment efforts achieve? About as much as Lee Myung Bak’s initial hard-line posture. The North Korean government doesn’t apologize when pushed up against the wall. And the North Korean people have not risen up against their rulers when pushed into starvation.

Joel Wit points out that diplomacy remains our most viable strategy: “In the aftermath of the Cheonan sinking, the United States and South Korea must recognize that a return to dialogue would serve our interests. It is the only realistic way to rein in North Korea’s objectionable activities.”

This is not a particularly palatable message right now in Seoul. And it probably won’t go down very well here in Washington. But after a couple months of denunciations and attempted arm-twisting, it would be best if the countries involved in the Six Party talks take this advice to heart. If we want to prevent any future Cheonans, we need to sit down with North Korea. The last thing we want is a country with nothing to lose and plenty of weapons to go out in a blaze of juche.*

*Juche: North Korea’s state ideology of self-reliance.