SYNOPSIS

Nuclear weapons might seem to allow Japan and South Korea to balance against their hostile and nuclear-armed neighbours, China and North Korea, respectively. In fact, this is not the case. Indigenous nuclear arsenals may create the very instabilities that both Japan and South Korea are seeking to offset.

COMMENTARY

In the wake of increasing ballistic missile and nuclear threats  from North Korea, South Korea recently signalled its willingness to seriously consider developing an indigenous nuclear arsenal. In a similar vein, a former United States defence official recently urged Japanese defence planners to exploit the “room … to broach the subject of deploying nuclear weapons, even if it is still too early for Tokyo to take action.” The presumption in both cases is that the indigenous nuclear arsenals will be subsumed under their respective mutual security treaties with the United States.

As I had argued before, nuclear weapons continue to exercise a terrible hold on both the popular imagination and the strategic thinking of defence planners around the world – from the science fiction TV series Battlestar Galactica to Bernard Brodie’s depiction of nuclear weapons in his book The Absolute Weapon (1946). Brodie had written: “Thus far the chief purpose of our military establishment has been to win wars. From now on its chief purpose must be to avert them. It can have almost no other useful purpose.”

Nevertheless, it is important to be absolutely clear as to how indigenous nuclear weapons will help both South Korea and Japan to address their respective strategic predicaments. And that clarity comes only through hard strategic thinking that avoids the motherhood expression ‘existential deterrence,’ which, to its adherents, means that the mere possession of nuclear weapons is sufficient to deter an existential threat. But what is the exact nature and character of the strategic ailment afflicting the two states, and precisely how is the possession of indigenous nuclear weapons the cure?

The Strategic Ailments of Japan and South Korea

At face value, Japan and South Korea face similar strategic ailments: a severe case of power imbalance, manifesting in the form of nuclear-armed and increasingly bellicose neighbours, China and North Korea, respectively.

Japan has alleged that China’s naval vessels intruded into Japanese territorial waters a total of 8 times between 2004 and 2022; 5 of them since October 2021. From March to December 2021, Chinese military aircraft allegedly intruded into Japan’s air defence identification zone (ADIZ) a total of 571 times.

Furthermore, China has repeatedly threatened to attack Japan if it were to intervene in a China-Taiwan military conflict. China has also reacted angrily in the past to any Japanese plans to increase defence spending, or worse, to any attempts to revise Japan’s pacifist post-1945 constitution. Before the summit meeting between US President Joe Biden and Japan Prime Minister Yoshihide Suga in April 1921, China threatened to sail a naval strike group including the aircraft carrier Liaoning, through Japanese waters near Okinawa.

Arguably, South Korea has an even more severe strategic ailment. It is neither able to stop or to deter North Korea’s repeated ballistic missile and nuclear weapons tests: six nuclear tests between 2006 and 2017, as well as an increasing frequency of  missile tests. In 2020, North Korea conducted four tests of missiles of varying types and ranges; in 2021, the number of tests doubled; and in 2022, there were over 90 tests of cruise and ballistic missiles.

These North Korean missile tests are merely the latest in a long list of provocations against the south, some of which have resulted in the deaths of South Korean civilians, law enforcement and defence personnel. In 2010, North Korea sank the ROK navy vessel Cheonan, resulting in the loss of 46 South Korean naval personnel. On the other hand, North Korean naval personnel have also been killed by South Korean naval gunfire in a number of clashes between both navies.

Of course, North Korean missile tests also threaten Japan’s strategic wellbeing since many of these tests involve overflight of Japanese airspace and exclusive economic zones. In November 2022, a North Korean ballistic missile being tested landed approximately 200km from Japan. Just a month earlier, North Korean media, in response to Japanese condemnation of repeated ballistic missile tests, warned that Japan “may see what a real ballistic missile is in the not too distant future.”

Clearly, the nuclear umbrella that the United States has extended to both states has failed to work in deterring China and North Korea from their bellicose behaviour.

How a Dose of Nuclear Weapons Can Cure these Ailments

However, are nuclear weapons the cure for the strategic ailments that Japan and South Korea suffer from? Can the indigenous nuclear weapons that they are thinking of developing provide a modicum of security for them?

At face value, it is a tempting option, based on a simple and beguiling logic. A bully behaves aggressively because the bully is (apparently) more powerful than the victim. One possible solution for the victim is to become as powerful as the bully, who will surely then stop the bullying. This analogy is an ever-present undercurrent in much of deterrence theory literature, which grew when the Cold War between the United States and the former Soviet Union crossed into the nuclear dimension.

Deterrence theory has a much older history than we think for the underpinning logic of deterrence – do not, for fear of the consequences – is as old as recorded history. In the 4th Century CE, the Roman thinker, Publius Vegetius Renatus, wisely advised: “si vis pacem, parabellum”, translated as “if you want peace, prepare for war.” Despite this, the argument that deterrence theory exists independent of nuclear weapons is almost never accepted in academic literature. This explains, at least in part, the attraction that nuclear weapons have for states with strategic ailments similar to that of Japan and South Korea.

Complications and Side Effects?

To complete the medical analogy of finding a cure for strategic ailments, taking medication may entail side effects and complications. And the nuclear medicine is no different.

For both Japan and South Korea, indigenous nuclear arsenals might appear to be a panacea to offset their strategic rivals’ nuclear advantages. North Korea, surely, must be more circumspective if its southern neighbour is also nuclear-armed. To borrow from Albert Wohlstetter’s 1958 RAND Paper, there would then be a “balance of terror” on the Korean peninsula. A similar case, also seemingly intuitive, can be made for relations between China and Japan: would China recklessly violate Japanese territorial waters or ADIZ if it faced a Japan that is capable of inflicting nuclear devastation upon Chinese soil?

However, this balance of terror, as Wohlstetter had portrayed it, is a delicate one. By the end of the Cold War, through much trial and error and happenchance, both the Soviet Union and the United States had constructed fairly robust mechanisms through which they managed their delicate balance of terror – from “hotlines” that connected the White House with the Kremlin; treaties that established limits to types of nuclear weapons, nuclear tests, and anti-missile systems; and confidence-building instruments such as those providing each other with alerts regarding missile tests and military exercises. In addition, and perhaps most significantly, both the Soviet Union and the United States had robust retaliatory nuclear attack capabilities; it meant that neither could gain a war-winning advantage by attacking the other first.

Without such robust systems to manage their nuclear rivalries, the inter-Korean and Sino-Japanese relationships will likely be fraught with potential dangers. Chief amongst these potential dangers is the “use ’em or lose ’em” mentality. If there is no capacity to retaliate after sustaining a nuclear attack, both Seoul and Pyongyang, as well as Beijing and Tokyo, will face intense pressures to initiate a nuclear attack against their respective adversaries, especially if one side or the other believes that its adversary will soon launch a nuclear attack.

To round up, nuclear arsenals for Japan and South Korea, and for any other state with similar strategic ailments, may appear to be a useful strategic solution, except that it is not. Instead, what these states need is greater strategic imagination to find unique solutions for their own ailments.

About the Author

Bernard F. W. Loo is a Senior Fellow in the Military Studies Programme of the Institute of Defence and Strategic Studies (IDSS), at S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University (NTU).