South Korea has laid down its third KSS-III (also see) of 3,000+ ton conventional attack submarines (SSKs) to carry 6 cruise or ballistic missiles. If the KSS-IIIs carry ballistic missiles they can be reclassified conventionally propelled ballistic missile submarines (SSBs).
It is unknown whether the missiles will be in separate vertical launch tubes along the hull or be in one more flexible Vertical Multi-Purpose Lock. Confusingly the KSS-III can also be called KSS3, Jang Bogo-III or perhaps Chang Bogo-III.
The ballistic missile to be carried in the early 2020s may be the Hyunmoo-2B with a range of 500km and warhead/payload of 500kg. 500km may be more a political minimum estimate signalling China or the China-North Korea border areas are not targets.
KSS-III’s could potentially carry:
- 800 km range Hyunmoo-2C ballistic missiles, or
- 1,000 km range Tomahawk like Hyunmoo-3 cruise missiles that could make China a target.
North Korea has little to worry about South Korea missiles that only have conventional explosive warheads. Kim could be protected in a deep bunker.
If there are rumours or an actual South Korean nuclear weapons program then South Korea could utilise independent nuclear deterrence – something North Korea will respect.
If Trump is no longer interested in extended US nuclear deterrence then Australia should also contemplate building an independent nuclear deterrent.
The map above indicates how close some North Korean nuclear facilities are to the Chinese border, particularly Yongjo-ri uranium enrichment site and Hyesan nuclear research site. If either site were hit with South Korean (SK) or US conventional explosives this may spill radioactive fragments from the facilities onto Chinese soil. This would bring China into any conflict. Use of US or future SK nuclear weapons on those sites would even more likely damage and antagonise China. (Map courtesy The Guardian).
This second map (courtesy The Economist) illustrates how constricted the waters are for South Korean (SK) submarines. Any SK cruise or ballistic missile submarines might be easily monitored by Chinese or North Korean submarines or undersea sensor/SOSUS arrays as the SK submarines leave port or move into vulnerable near seas (Sea of Japan, Yellow Sea or East China Sea) for missile launches.
Relatively distant Western Pacific waters would be safer but that may mean SK submarines need missiles of 2,000 km range - something likely unachievable now - unless Tomahawks from the US are used.