New Follow-Up on the Cheonan Sinking

I've complained against not following up on news here before, but the Cheonan sinking story is still getting updates. Perhaps because some still wait for an U.N. resolution or the matter, or because it just makes for an interesting read, but more info comes out pretty regularly.

The following is about submarines and naval exercises, read it if you like Tom Clancy or submarines or something. The pictured sub is a larger Sang-O class which surfaced and was captured in '96, not the kind blamed for the attack.

U.S. and South Korea held a joint naval exercise on the day of the sinking. 2 U.S. destroyers and various other ships were playing hide and seek with a South Korean submarine. The Cheonan wasn't a part of this drill, it was on routine patrol, but perhaps these two weren't very far away.

Also, Cheonan was running on active sonar. This is significant in that the shooting could have been a panic move. A North Korean submarine could have been in the area monitoring the military exercise and find the corvette (either by having acquired it by sonar or by coincidence) coming straight at it. The waters around the area aren't very deep and the small submarines aren't very fast, they are very quiet. It's possible, among other possibilities, that the North Korean captain felt his only option is to fire first or see what the corvette does to him.

As an aside, submarines should be able to identify the active sonar source by sound frequency so that any submarine in the area should know whose active sonar is being used, except for very outdated sonar equipement.

It is also possible the military exercise went wrong and that it was a friendly fire incident. This is much more unlikely however. The hunted South Korean submarine wouldn't launch a live torpedo in an exercise and Cheonan wasn't even a part of the group hunting the sub. It is however possible that it was a live torpedo by mistake - if the submarine was looking for a friendly warship on purpose it just takes a human error to fire a live weapon.

Pauline Jelinek for AP reported the facts from my speculation:
http://news.yahoo.com/s/ap/20100606/ap_on_go_ca_st_pe/us_us_korea_ship_sinking

Please note, that behind the link monstrosity an U.S. official anonymously admits that it might have been an accident or an error instead of an attack from the North.

Coming to monitor the opposing navies would explain why a submarine and a tender left North Korean harbor just days before the incident. If anything there should be reasonable doubt as to how and why the incident occurred to not blame North Korea yet.