On May 20, South Korea announced the results of an investigation by a team of 25 military experts and scientists from five countries into the March sinking of the South Korean corvette Cheonan. The report concluded that the ship had been sunk by a North Korean CHT-02D torpedo fired from a submarine.

The following is a purely military interpretation of what Taiwan can learn from the incident.

First of all, the submarine is a weapon that gives weaker parties an asymmetric advantage. The US and South Korea have not made clear that at the time the Cheonan was sunk, they were engaged in a large-scale joint military exercise. If the evidence is correct, then the question arises how the North Korean submarine managed to slip through their monitoring system along with high-tech navy and air force anti-submarine measures. This highlights shortcomings and weaknesses in the US and South Korean high-tech navies’ submarine surveillance capabilities.

On May 30, the New York Times ran an article saying that the US military was very surprised that a South Korean warship could be so easily sunk by a torpedo from a North Korean submarine and unable to detect and stop this kind of attack after having spent such huge sums on its navy over many years.

Admiral Mike Mullen, chairman of the US Joint Chiefs of Staff, also said in an interview that the US and South Korea are now planning a joint military exercise with the long-term objective of developing ways to stop this kind of miniature submarine, although that would seem to be a very difficult problem, both technically and tactically.

In response to the Korean conflict, the US dispatched the Seventh Fleet’s carrier battle group to participate in exercises and for monitoring purposes. However, as South Korean President Lee Myung-bak gave a speech to the nation announcing that his government would block North Korean merchant ships from passing through the Jeju Strait, four North Korean Shark-class submarines left the Chaho naval base in northeastern North Korea and then disappeared without a trace. The question now is if other similar incidents will occur.

Second, President Ma Ying-jeou (馬英九) and his administration have not expressed clear support for obtaining submarines. Although the provocative actions of North Korea, are not to be imitated, the sinking of the Cheonan is significant from a strategic military perspective because it makes clear that a party that finds itself at a disadvantage can still gain an asymmetric advantage and that the submarine is one weapon to accomplish this.

In addition, it is impossible to determine whether modern weaponry, expensive or cheap, is of an offensive or a defensive character. Instead, that will depend on the user. Ma’s national defense policies are focused on defense, but then to define the submarine as an offensive weapon is biased. This is why for many years I have stressed the necessity of developing short-range submarines to deal with China’s rising force. That option is both inexpensive and effective.

Ma keeps stressing that Taiwan must develop sufficient defensive strength, but director of the US-based Taiwan Security Analysis Center Fu Mei (梅復興), a long-time observer of Taiwan’s defense, said on May 14 that while Ma over the past year or more has made repeated public calls for US arms sales, in practice he has not been pushing very hard.

Maybe the western Pacific will not see full-blown war in the future, but there will always be a possibility for conflict. At the moment, the cross-strait situation is relaxed, but in the future, Taiwan must seriously consider how to deal with and prevent domestic Chinese problems from developing into external conflict.

Wang Jyh-perng is an associate research fellow at the Association for Managing Defense and Strategies.

TRANSLATED BY PERRY SVENSSON