North Korea has over the last 10 to 20 years been developing what is called an "asymmetric strategy," which involves focusing on areas, however small, where South Korea is inferior to the North or lacking altogether. One part of this strategy is submarines. The North is believed to have a fleet of around 70 submarines, including some 20 1,830-t Romeo-class subs and 20 330-t Shark-class subs. The subs had been considered only a minor threat, due to their age, noisy engines and inability to operate in the shallow coastal waters of the West Sea. But the sinking of the South Korean Navy corvette Cheonan could radically change that perception.
There are growing concerns in the South Korean military that its anti-submarine warfare capabilities may not be up to the challenge. The South Korean Navy's battleships, 10 submarines and P-3C Orion anti-submarine and maritime surveillance aircraft can detect subs, but there is considerable skepticism about their ability to incapacitate the entire North Korean submarine fleet. Former South Korean defense minister Kim Jang-soo said recently that he heard the military is capable of detecting less than 50 percent of North Korean submarines.
Another area that needs improvement is the ability of South Korean naval ships to deal with mines. A U.S. military official reportedly said early last year the South needs to drastically strengthen its ability to combat mines. The fact that a mine was initially considered the most likely cause of the sinking of the Cheonan demonstrates the Navy's apparent weakness in detecting and defusing mines.
North Korea's nuclear, biological and chemical weapons as well as its ballistic missiles are another key component of its asymmetric strategy. The communist country is believed to have six to eight nuclear weapons similar in strength to the atomic bomb that was dropped on Hiroshima. It is also believed to have between 2,000 to 5,000 tons of chemical weapons, making it the world's third largest arsenal. It has around 10 different types of biological weapons as well. A thousand tons of chemical weapons is believed to be enough to kill 40 million people on the Korean Peninsula.
Around 350 long-range North Korean artillery pieces including 170 mm self-propelled howitzers and 240 mm multiple-launch rocket systems are lined up on the border and trained at Seoul and other South Korean cities, while 1,000 ballistic missiles, including 350 Scud and Rodong missiles, also pose a huge threat. If North Korea unleashes its artillery shells over the border, 100,000 Seoul residents could be killed or injured in just an hour.
North Korea also has around 180,000 special forces troops, the largest contingent in the world, who are constantly ready to be deployed behind South Korean military lines through Antonov AN-2 transport planes, helicopters, submersibles and hovercrafts.
South Korea's strategy is to use its F-15K and other cutting-edge fighter jets, Aegis destroyers and K-9 self-propelled howitzers in conjunction with U.S. military firepower to deter or contain a North Korean threat in its initial stage. But the asymmetrical strategy is capable of neutralizing such conventional responses, prompting experts to call for more specialized measures to deal with the threat.