On a chilly evening in late March, a South Korean naval ship called the Cheonan was conducting routine exercises in waters just off the coast of a sparsely populated island in what the Koreans call the West Sea (better known as the Yellow Sea), only about 10 km from North Korean land. It was just before 9:30, and for most of the ship's 104 crew members, work was done for the day. Some sat in the ship's mess chatting; others were exercising in a small gym. A few had already headed to their bunks for a night's rest. The ship's commanding officer, Choi Won Il, had retired to his cabin for the night and was checking e-mail.
What happened next would shock and anger many South Koreans and roil the country's politics. It would also contribute heavily to a deteriorating diplomatic and security climate not just on the Korean peninsula but throughout East Asia. Within a few weeks, the South Korean government privately became convinced that a North Korean "midget" submarine had fired a torpedo that sank the Cheonan, killing 46 sailors. They went public with that suspicion on May 20. The South Koreans had dredged up the shattered vessel in sections and recovered the remains of what it claimed was the North Korean torpedo.
The North Koreans have steadfastly denied the accusation and thanks to support from China and Russia, both members of the U.N. Security Council managed to successfully tamp down international outrage over the incident. On July 9, the U.N. Security Council issued only a "presidential statement," a milquetoast declaration that condemned the attack on the Cheonan but failed to identify who the attacker might have been. Ever since, President Lee Myung Bak's government in South Korea has vowed to release the full investigative report done by an international team (which brought in experts from the U.S., the U.K., Australia and Sweden). It is a document Seoul says will prove conclusively that, in the words of Kim Tae Hyo, Lee's senior adviser on relations with Pyongyang, "there is no other plausible explanation" except that a North Korean torpedo sank the Cheonan.
In South Korea, where attitudes toward the North go to the core of the country's politics, opposition politicians have expressed deep skepticism about the official line that Pyongyang was at fault. Choi Moon Soon of the opposition Democratic Party, a member of the national assembly, is typical. He told TIME on Aug. 13 that he believes the ship simply ran aground and that the government had concocted the whole North Korea attack story as a way to influence local elections that were held on June 2. (Elections that Lee's ruling party actually lost.) He says he doesn't believe the government will ever publish the report and questions whether it even exists.
It does. The document, a draft of which has been seen by TIME, consists of 286 pages of sometimes dense scientific and engineering analysis. Not only does it present the case for why a North Korean attack is the "only plausible possibility," but also, sources with detailed knowledge of its preparation say its intent is to pick apart, in a manner worthy of a Sherlock Holmes story, the most prominent competing theories that have been publicly raised in the months since the sinking. There is no way the ship ran aground, the report says, because the damage to the Cheonan's hull was in no way consistent with that scenario. To the contrary, "two types of hull deformations, impossible to occur in a grounding event, were observed."
The possibility of a friendly-fire episode, widely debated on the Web in South Korea and elsewhere, is similarly dismissed. The report asserts that all "submarines from neighboring countries were either in or near their home bases at the time of the incident." A collision with another boat? No trace of an "incoming vessel" was found. A ship-to-ship or ground-to-ship missile? The damage done to the Cheonan, the report states, would have been considerably different had that happened. In all, the report considers 10 possible scenarios of why the ship might have sank, and after outlining the evidence in each of those cases, it concludes with the words, "No chance."
By contrast, it labels the notion that a North Korean torpedo struck and sank the Cheonan a "high possibility." It asserts that the survivors of the Cheonan heard "one or two explosion sounds" and that South Korean marine sentries posted on nearby Baekyrong Island testified to seeing "a flash of white light" about 100 m in height. The report further states that analysis done by the U.S. Navy for the joint commission concluded that the sub fired a torpedo with an explosive weight of 250 kg that blew up just under the center of the boat, to its port side, at a depth of 6 to 9 m. A detailed technical discussion of "shape and trace analysis" explains why the damage done to the Cheonan's hull is consistent with a torpedo attack.
It is unclear whether the full report will satisfy the outside academic skeptics who have raised questions about the government's conclusion. For example, Lee Seunghun, a physicist at the University of Virginia, has questioned, among other things, why the numeral 1, written in marker on the torpedo fragment that the government recovered on May 15 and displayed at a press conference five days later, did not evaporate, given the heat generated in an explosion. (The report states that the portion of the torpedo on which the markings were found part of its propulsion system was pushed back upon detonation and thus escaped the heat generated by the blast.)
Presidential adviser Kim, who sits on Seoul's National Security Council, says the report is in the final stages of preparation for public release, which will happen "soon." Others sources in Seoul have suggested it will be issued within two weeks. By releasing the full report, the South Korean government may at minimum succeed in putting its domestic political critics onto their back foot. Indeed, some conservative politicians in Seoul have conceded that the government should already have made the detailed report public. "They've made some mistakes," says Chung Ok Nim, a national assemblywoman in Lee's ruling party.
The report will have repercussions beyond Seoul. It could conceivably generate more heat for both China and Russia, given their roles in carrying North Korea's water in the Cheonan affair at the United Nations. China even initially opposed the weak presidential statement the U.N. Security Council issued, diplomatic sources have said. Beijing modified its stance when presented with the joint investigative group's report earlier this summer but then protested loudly when the U.S. and South Korea announced plans to stage five-day naval exercises as a response to the attack. The Lee government invited the Chinese to send a delegation to review the findings of the joint investigation group together, but Beijing declined.
That's probably not surprising. The report appears pretty damning, and once it goes public, Beijing, as the North's sole economic lifeline and diplomatic big brother, will likely just want to change the subject. It's hard to argue with South Koreans who believe the Cheonan attack was an act of war, and just as hard to argue that Pyongyang is paying much of a price for it.