To understand why North Korea sank a South Korean navy vessel, one must be aware of the circumstances surrounding the Battle of Daecheong. Likely, few, if any, on this website has ever heard of it.
The Battle of Daecheong took place in November 10, 2009 near Daecheong Island at the Northern Line Limit. The Northern Limit Line was set by U.S. forces in 1953 but has never been recognized by North Korea nor is it mentioned in the 1953 Armistice Agreement. Initially, it was drawn to prevent South Korea to cross north, but has since been changed to prevent North Korea from crossing south.
Over the last half century, North Korean fishing boats have routinely crossed the line, many times escorted by N.K. patrol boats. Prior to the Battle of Daecheong, there had been two minor skirmishes along the border, the first and second Battles of Yeonpyeong, in 1999 and 2002 respectively.
Here is a description of the Battle of Daecheong:
The incident began around 11:27 am when a North Korean navy patrol boat crossed down through the NLL even though boats from the South Korean navy warned them twice. After one more warning announcement, one of the South Korean patrol boats fired a warning shot. In response, the North Korean boat began firing upon the South Korean ship. This resulted in a short exchange of fire between the sides. The North Korea vessel expended approximately 50 rounds, and the South Korean craft returned fire with 200 rounds.
The Korean Central News Agency, the official news agency of North Korea, accused the South Korean Navy of provoking the confrontation, reporting that "the North side let a patrol boat of the Navy of the KPA on routine guard duty promptly go into action to confirm an unidentified object that intruded into the waters of its side. When the patrol boat was sailing back after confirming the object at about 11: 20 a group of warships of the South Korean forces chased it and perpetrated such a grave provocation as firing at it. The patrol boat of the North side, which has been always combat-ready, lost no time to deal a prompt retaliatory blow at the provokers. Much flurried by this, the group of warships of the South Korean forces hastily took to flight to the waters of their side."
After the battle, the South Korea patrol boat had suffered only superficial damage (reportedly 15 bullet marks on the ship's side) with no casualties, while the North Korea patrol boat was left partially destroyed. Though there was no official announcement from North Korea, a news agency in South Korea reported a rumor that North Korea suffered four casualties (1 KIA / 3 WIA). On the other hand, a defector said about 10 North Korean sailors were killed in action.
Not to justify the North Koreans, but simply to give this situation the proper context, one could just as easily claim that these waters are in North Korea as South Korea. In fact, one can better understand the domestic pressures upon Kim Jong-il if one considers that from the North Korean perspective the Battle of Daecheong represented the attack of one of their vessels in their own territory.
This is why it was theorized afterwards that General Kim Myong-Guk was demoted after the battle.
The JoongAng Daily published photos of General Kim Myong-Guk released last June and this week. The earlier picture showed Kim with the four stars of a full general, while this week’s photos showed just the three stars of a colonel-general....
...One theory is that General Kim was demoted over North Korea’s beating in the last naval clash with the South.
Now spring forward to March 26,2010. The Chenoan goes down near the Northern Limit Line near the South Korean island of Baengnyeong. A torpedo attack is suspected.
Then in April, North Korea celebrates the 78th Anniversary of the Korean People's Army
The training well showed the decisive resolution and merciless striking force of the KPA soldiers replete with the fighting spirit to annihilate the aggressors at one stroke, if they dare intrude into the inviolable land, sea and sky of the DPRK even an inch, and take thousand-fold revenge upon them.
and who is in attendance and sporting a fourth star again? General Kim Myong Guk.
A key general in the North Korean Army has been returned to four-star rank after a demotion earlier this year, and South Korean government and intelligence officials are scrambling to find out why.
It is not until May that the Chenoan Report comes out:
The South Korean corvette Cheonan was split in two by the shockwave and bubble-jet effect resulting from the underwater explosion of a 250 kg torpedo.
The parts dredged up from the sea floor where the Cheonan was sunk match the schematics of a weapon offered for sale by North Korea, the CHT-02D torpedo.
A hand-written Korean inscription, translating to "No. 1," was found on one such part. The same marking appears on a North Korean torpedo found by the South seven years ago.
"A few small submarines and a mother ship supporting them left a North Korean naval base in the West [i.e., Yellow] Sea 2-3 days prior to the attack and returned to port 2-3 days after the attack."
No other country had a submarine in the area at the time.
It becomes obvious that North Korea was behind the attack on the Chenoan, that the Battle of Daecheong was seen by North Korea as an attack on a NK vessel in NK waters and that Gen. Kim Myong Guk was given a chance to redeem himself by avenging that attack.
The key to resolving this issue peacefully is not to ratchet up sabre rattling on both sides. The key to resolving further incidents like this is to resolve the boundary dispute created by the U.S. unilaterally imposed demarcation of the Northern Limit Line. Until both sides agree upon who controls these disputed waters, confrontations like this are going to continue and war, not peace, will be the outcome. Ideally, a buffer zone should be set up. One that keeps both navies away from each other but would allow fishing vessels to safely operate within it.