North Korea is once again ratcheting up its threats, and they appear to be more serious than ever. On 8 May, North Korea manifested its nuclear missile capacity by test-firing a submarine-launched ballistic missile. On the same day, the North sent notice from its Southwestern Frontline Command to Cheong Wa Dae&’s Bureau of National Security, threatening to annihilate South Korean naval vessels without warning should they violate the West Sea Maritime Military Demarcation line unilaterally drawn by the North. The next day, Pyongyang fired three ship-to-ship missiles believed to be KN-01s into the East Sea, daring South Korea to retaliate.

Pyongyang&’s intentions to dominate inter-Korean relations with such asymmetrical capabilities have been clear since the early 1990s, when it first revealed its nuclear ambitions. Since then, it has conducted three nuclear weapons tests and has been avidly developing missile projectiles. The situation is therefore quite unfavourable for Seoul, since its vulnerability vis-a-vis the North&’s asymmetric threat undermines its North Korea policies and nullifies its efforts for a democratic reunification. Despite these risks, South Korea&’s response seems to centre around missile defence and preemptive capabilities that have limited feasibility, thus pushing aside how to secure mutual vulnerability.

North Korea is governed by a hereditary dictatorship and could therefore focus all its energy on strengthening asymmetric power over the South. But South Korean politicians seem to be more interested in elections, and establishing a long-term plan for a strategic balance between the two Koreas has probably never been a priority concern for many of them. South Korea must now hurry to establish a balance of terror based on “mutually assured destruction” or “mutual vulnerability.” For this, it should refer to the proactive deterrence strategy proposed by the Presidential Commission for Defence Reforms in 2010.

During the Cold War, mutually assured destruction was the centrepiece of deterrence strategy that prevented a nuclear war. At that time, SLBM-armed submarines covert platforms that can retaliate against an enemy attack without being detected were recognised as “the most stabilising second strike forces” that made the two superpowers vulnerable to each other and deterred one&’s nuclear attack against the other. Unfortunately, on the Korean peninsula, the North is going to add SLBMs to its nuclear arsenal on the top of the South&’s unilateral vulnerability. Of course, South Korea&’s attempt to intensify the so-called Korean Air and Missile Defence system or construct a pre-emptive system, which the Defence Ministry calls a “kill-chain,” should be valid and necessary.

But, the North&’s SLBMs, if completed and deployed, may easily evade preemptive strikes and penetrate the defence system, thus allowing Pyongyang to more blatantly taunt and threaten Seoul. What is more urgent for South Korea, therefore, is adopting a new retaliatory strategy supported by powerful second-strike forces. A conventional triad, which means deployment of effective retaliatory weapons with precision, lethality and survivability on the ground, in the air and on and under the sea, could constitute such second-strike forces, as suggested by the Presidential Commission in 2010.

In conclusion, from now on South Korea needs to pay more attention to “retaliation,” while its efforts toward better “defence” and “pre-emption” are also necessary. Therefore, the Defence Ministry&’s latest plans for spending 8.7 trillion won for KAMD and kill-chain for the next five years may need rethinking. It may now be the right time for political leaders to tear themselves away from their feuding and corruption scandals to face Pyongyang&’s threats and think about how to best allocate the defence budget toward strategic stability on the Korean Peninsula.

They also need to heed the fact that South Korea&’s pressing security issues are fading into peripheral variables amid the renewed ties between the USA and Japan, and those between China and Russia.