By Jun Ji-hye



While politicians are calling for the development of a nuclear-powered submarine amid mounting threats of North Korea's submarine-launched ballistic missile (SLBM), the military is taking a cautious stance, apparently wary of possible repercussions from the United States.



Members of the ruling Saenuri Party and some experts say the only measure to counter the North's SLBM threat is possessing nuclear subs that can operate at high speeds for long periods of time, but critics point out that the nation will face many problems to develop them.



The first question is whether the United States, which virtually controls the uranium enrichment and nuclear fuel reprocessing of South Korea, would approve of Seoul's uranium enrichment activity to operate a nuclear sub.



Some say that a revision of the Seoul-Washington nuclear cooperation deal, signed last year, would allow Seoul to enrich uranium to a level of 20 percent when using U.S. ingredients, but critics point out that the agreement disallows the uranium enrichment for military purposes.



Yang Uk, a senior research fellow at the Korea Defense and Security Forum, told reporters that it is not hard to anticipate Washington's negative response to Seoul's move to develop a nuclear sub as the country tends to be reluctant to allow its allies to have strategic weapons.



Although a nuclear sub is not armed with nuclear weapons but uses nuclear fuel as a power source only, the development can still provoke controversy over whether or not the South Korean government shifts its position from the 1992 inter-Korean denuclearization declaration. Ahead of this, South Korea ratified the nuclear Non-Proliferation Treaty (NPT) in 1975 and has remained formally committed to it since then.



"Whether to build a nuclear sub is closely related to the government's principle of denuclearization, so it is not a simple question," a military official said on condition of anonymity.



The ensuing questions are possible protests from neighboring countries, especially China, which has already been protesting the planned deployment of a U.S. Terminal High Altitude Area Defense (THAAD) battery on South Korean soil by next year. China believes that the battery's AN/TPY-2 radar could be used to spy on the country's military activities and missiles, although Seoul and Washington maintain the stance that the system is designed to defend against North Korean missiles only.



Experts say Seoul's development of a nuclear sub could lead Japan to develop its own subs and push for nuclear armament, which would consequently cause a fierce arms race in the Northeast Asian region.



"From China's point of view, if the development of nuclear submarines is realized in Seoul and Tokyo, it would threaten Beijing's national security much more than THAAD would," said Park Won-gon, an international relations professor at Handong Global University.



Talk about the need to develop a nuclear sub has gained momentum here after the North successfully fired an SLBM, Aug. 24, which flew about 500 kilometers and landed in Japan's Air Defense Identification Zone (JADIZ) in the East Sea.



Rep. Chung Jin-suk, floor leader of the ruling party said, Monday, "The military should consider getting nuclear submarines that can deal with North Korea's SLBMs as they are a more serious threat compared to other land-based missiles as it is difficult to detect the launch point."



A nuclear sub can stay submerged and hidden as long as it has fuel and supplies for its crew, making it harder to track compared to conventional diesel-electric subs that have to surface frequently and operate a diesel engine to recharge their batteries.



Supporters for having nuclear subs say such vessels can be assigned to patrol around North Korean submarine bases, without being detected, and trail SLBM-armed subs heading out to sea.



