In a recent interview, South Korean President Park Geun-hye said, "It would be difficult for us to prevent a nuclear domino from occurring in this area," were North Korea to conduct another test. But one analyst argues that if a nuclear arms race were to occur, it's China that should be singled out for blame.
President Park—whose comments were published in the Wall Street Journal—warned that a fourth nuclear test by North Korea "would effectively be crossing the Rubicon," compelling non-nuclear weapon states in Asia to acquire a nuclear deterrent against Pyongyang.
However, Zachary Keck, an editor and reporter specializing in defense and security issues, dismisses Park's predictions as "merely bluster." As he notes in The Diplomat:
This view is premised on the argument that states acquire nuclear weapons to deter rival nuclear armed states. This was true in the early nuclear era when non-nuclear states had no reason to believe that their nuclear-armed rivals would not use nuclear weapons against them.
As the nuclear era progressed, however, it became clear that nuclear weapons would not be used in the same manner as other military capabilities would. In the words of many, a taboo against the first use of nuclear weapons took root. This taboo is especially strong when it comes to using nuclear weapons against a non-nuclear state.
North Korea would be particularly unlikely to break this taboo…attacking Seoul or Tokyo with nuclear weapons would almost certainly invite a retaliatory nuclear strike from the U.S…..South Korea and Japan understand all this and therefore would not endure the enormous costs (especially to their international reputations, alliances with the U.S., and relations with China) inherent in acquiring a nuclear weapon.
Although North Korea is unlikely to precipitate a nuclear arms race in Asia, China's growing military capabilities and assertive diplomatic posture very well might. Indeed, just as history has demonstrated that states don't need nuclear arsenals to deter rivals from attacking them with nuclear weapons, it has also demonstrated that nuclear weapons are extremely effective in deterring conventional military attacks. Thus, states that face rivals with overwhelming conventional military power have a strong incentive to acquire nuclear weapons to negate their rivals' conventional superiority.
This is especially true if a state fears that its conventionally superior rival covets its territory. A nuclear arsenal cannot always deter low-level skirmishes from nuclear and non-nuclear powers. But nuclear weapons are extremely effective at deterring states from challenging core interests, first and foremost territory.
[Source: The Diplomat]