Japan's Nuclear Strategy

Nobukatsu Kanehara

Time to Start a Nuclear Debate

Before his untimely death, former Prime Minister Shinzo Abe bravely initiated a discussion on Japan's nuclear strategy, calling for the country to consider nuclear sharing. He was the first Japanese statesman to publicly address this topic. Sadly, his life was cut short by an assassin's bullet, and the nuclear debate he initiated has since been silenced.

The debate on Japan's security issues has been dominated by the ideologically-biased and divisive discussion since the formation of the 1955 system—a domestic political system that featured the confrontation between the conservative Liberal Democratic Party of Japan and the Japan Socialist Party—following the internalization of the Cold War into the domestic politics. Real issues related to the national security are discussed only in secret at the Ministry of Foreign Affairs in Kasumigaseki and the Ministry of Defense Agency (then located at Roppongi). Even then, the issue of nuclear weapons was taboo.

As the Cold War proceeded, tens of thousands of nuclear weapons were produced and deployed; Japan, as the primary US ally in the Pacific, faced the threat of Russian nuclear warheads pointing at it; American nuclear weapons were brought to Okinawa under US military rule and to South Korea. Nonetheless, no mature discussion on nuclear strategy failed to emanate from Japan. Japan who is the only country on the globe that suffered atomic bombings in Hiroshima and Nagasaki, fails to have a strategy to protect its citizens from nuclear weapons. The reason for this lies in the domestic political environment under the 1955 system.

Under the 1955 system, the position of the government and the Liberal Democratic Party was to maintain the Japan-US alliance and to enhance Japan's defense capabilities. Defeated in the Pacific War, Japan was allowed to form only a medium-sized Self-Defense Forces. To counter the powerful communist blocs in the Far East of Russia, China, and North Korea, and especially to counter the threat of the Soviet military in the Far East with its massive nuclear arsenal and 400,000 troops, Japan needed to strengthen its national defense capabilities with the Japan-US alliance. With two prominent prime ministers, Shigeru Yoshida and Nobusuke Kishi, at the helm of government, post-war Japan swiftly restored its relations with the West, strengthened its defense posture, created a new military force named the Self Defense Forces, and joined the free trade system of the West, thereby working on the path to economic recovery.

In contrast, the Japan Socialist Party, the country's leading opposition party, approached the eastern camp led by the USSR. Many political parties in Western countries—the American Democratic Party, the British Labor Party, the French Socialist Party, the German Social Democratic Party, etc.— represent the interests of trade unions, but, unexceptionally, they have a distinct position of being members of the West. The JSP was the only opposition party in a major Western country that pledged its allegiance to Moscow. The Japanese Diet and public opinion split over many political issues due to the existence of the JSP, which, however, never came to power. As a result, Japan had not virtually been a member of the West as far as security policy was concerned until Prime Minister Yasuhiro Nakasone took office and declared, "Japan is a member of the West." In his famous book "World Order," Dr. Kissinger wrote of Japan in the 1970s, when he was in charge of US diplomacy, that "Japan placed itself legally in the camp of the developed democracies but—citing its pacifist orientation and commitment to world community—declined to join the ideological struggles of the age." He says that it was a country likened to a chimera. Unfortunately, this was an unbiased description of Japan at the time.

The "unarmed neutrality" policy proposed by the JSP is identical to one that Russian President Vladimir Putin now attempts to force on Ukrainian President Zelensky after his illegal invasion of Ukraine. Putin demands: "Sever ties with the United States. Be neutral and minimize your troops." This is the same with the "demilitarized neutrality" that the JSP advocated as Japan's security policy in the post-war era. It was nothing but representing Russia's interests while neglecting Japan's security.

In a situation without a national consensus on security, one of the most vehement Diet debates took place over the credibility of the US nuclear deterrent, or the so-called "nuclear umbrella." In the Diet debate, the JSP and the Japanese Communist Party tried hard to diminish the credibility of the Japan-US alliance.

In particular, the opposition parties focused on the issue of the US "introduction" of nuclear weapons into Japan. The "introduction" of nuclear weapons does not only mean their deployment on the ground, as in South Korea and Okinawa. It also means a call at a port for fuel supply by US Navy vessels equipped with nuclear weapons. Resolute not to allow even such a port call, the opposition parties argued against the "introduction" of nuclear weapons and tried hard to thwart the US nuclear strategy. To this end, they capitalized fully on the anti-nuclear sentiment of the Japanese people.

Attempts to ban US nuclear-carrying vessels from calling at Japanese ports as the "introduction" of nuclear weapons are no more meaningful than anti-nuclear propaganda. Since launching tactical nuclear weapons from US carrier-borne fighter aircraft, surface ships, and submarines is supposed to take place outside Japanese territory, Japan has no authority over their deployment or operation. Port calls for refueling and resupplying do not indicate that Japan will become involved in the US nuclear strategy. US "introduction" of nuclear weapons, in the true sense of the word, should mean landing nukes on the soil of a US ally, accompanied by a close discussion about their deployment and operation with the ally.

To begin with, the United States adopts a policy of "no declaration, no confirmation" as to whether or not to deploy nuclear weapons on carrier-borne fighter-bombers, surface ships, and attack submarines belonging to the US Carrier Strike Group in order to complicate calculations on the enemy's side. Japan's policy of not allowing nuclear-armed US warships to call at Japanese ports made no sense from the outset.

However, influenced by the intense anti-nuclear public sentiments, the Japanese government insisted that no nuclear weapons were carried on US vessels calling at Japanese ports as long as it received no prior notification. After the Cold War ended, the US removed nuclear weapons from all of its naval vessels, and the issue of bringing in nukes to Japanese ports vanished spontaneously. Later, under the Democratic Party of Japan administration, the fictitious scheme of introducing US nuclear weapons was revealed.

In this political atmosphere, the ideal of nuclear abolition drifted from reality, and many discourses went so far as to say that the practical theory of nuclear deterrence was at odds with the ideal of nuclear abolition. According to international common sense, nuclear abolition, nuclear arms control and disarmament, and nuclear deterrence are interrelated issues along a continuous policy line. Although nuclear abolition is an ideal, nuclear states are still fascinated by the destructive power of nukes and hold fast to them. Although arms control and disarmament progressed rapidly in the late Cold War years, a rising China was busy producing more nuclear weapons; outside the NPT regime, North Korea, India, Pakistan, and Israel, which did not officially admit the fact, became nuclear states. Countries sandwiched by nuclear states have no choice but to depend on the nuclear umbrella provided by their nuclear allies.

In Japan, however, many argued, "If we are committed to the ideal of nuclear abolition, we should not depend on the US nuclear deterrence." This was nothing more than a partisan and ideological argument consistent with Russia's interests at the expense of Japan's national security.

Prime Minister Abe's remarks quoted at the beginning of this essay jolted the boundaries of the nuclear taboo forged by the 1955 system. Abe did not state that nuclear sharing with the United States should start immediately but meant that Japanese political leaders are responsible for beginning a nuclear debate persuasive to the people.

At present, Russia publicly mentions the early use of tactical nuclear weapons in Ukraine, while North Korea is busy developing nuclear weapons and missiles to deliver them. Above all, China, which has begun to demonstrate its huge power, publicly states that it will annex Taiwan by force if necessary; the country is rapidly increasing its production of nuclear warheads. The CIA estimates that China's nuclear warheads will increase to 1,500 by 2035. That number is equal to that of nuclear warheads that the United States is allowed to deploy at any time under the now-suspended New START Treaty. Japan now stands at the bottom of the most dangerous nuclear valley in the world. At this juncture, it is not excusable for political leaders to evade public debate on the issue of nuclear deterrence. What are they escaping from in the first place? The people demand to be informed.

Improving the Credibility of the Nuclear Umbrella and Reassurance to Non-Nuclear Allies

When it comes to nuclear deterrence, a special psychological dynamic works between nuclear allies and non-nuclear allies, particularly when the non-nuclear allies are positioned at the front lines.

In 2018, when the INF Treaty between the United States and Russia was abrogated, Prime Minister Abe asked the present author to brief him on the matter. At that time, I said, "Germany, as a front-line state, is very sensitive to nuclear issues, which led to NATO's nuclear-sharing arrangement. Conversely, Japan has unconditionally trusted the United States regarding nuclear issues. From the US perspective, I think Japan is an easy country to deal with." Listening to my explanation, Abe frowned and sniffed. Perhaps he thought that the previous Japanese governments had been too irresponsible on nuclear issues.

West Germany was a front-line state during the Cold War. Germany split into two parts, and West Berlin was isolated in East Germany; huge phalanxes of Red Army tanks were arrayed beyond Hamburg in West Germany. Unlike today, an oppressive air hung over the city of Hamburg before the end of the Cold War. If deterrence were broken, the Red Army's tank corps would advance promptly. Unless tactical nuclear weapons were employed, there would be no way to stop the Soviet tanks. But if West Germany used nuclear weapons, the Warsaw Pact forces would also resort to nukes. The frontal opponents that West Germany would fight were the same ethnic Germans. If East and West Germany were exterminated by exchanges of nuclear weapons, the United States, Britain, and France would not engage in an all-out nuclear exchange with Russia but sign a cease-fire agreement, restoring peace in Europe—without Germany. The person who feared this most was West German Chancellor Helmut Schmidt, who took the lead in addressing the Euro-Missile Crisis of the 1980s.

This "sacrificial pawn psychology" haunts the non-nuclear allies on the front lines. Therefore, Germany chose to become entangled in the US nuclear strategy whenever possible.

During the Cold War, Germany confronted the mighty Red Army's tank corps; numerous US tactical nuclear weapons were brought into the country from the early stages of the war. At the time, those weapons passed simply as "big bombs." The credit for introducing those weapons belonged to a peremptory decision made by West Germany's resolute Chancellor Adenauer. As a significant quantity of US nuclear bombs found their way into the country, it was natural for Germans to inquire when and where to strike and to demand their involvement. In due course, they claimed involvement not only in the deployment but also in the operation of those weapons. The German Bundestag passed a resolution in the 1950s to acquire nuclear weapons delivery means. That desire was satisfied by the acquisition of dual-use fighter aircraft such as the F-16. Furthermore, Germany claimed NATO's independent operation of nuclear weapons; as a result, NATO's nuclear-sharing arrangement developed in which US nuclear bombs were deployed at air bases in Germany, Italy, the Netherlands, and Belgium; ultimately, they were delivered to the air forces of these NATO allies. At present, 100 B61 air-dropped bombs are reported to be deployed in Europe as NATO nuclear weapons.

Japan's Nuclear Strategy

Unlike Germany, which was then on the brink of warfare, Japan was free from existential anxieties during the Cold War. War with Russia was no more than a European war; NATO was powerful. Tens of thousands of US nuclear missiles were pointed at Soviet Russia across the Arctic Ocean. A third world war would not happen so easily. From the 1970s onward, the Sino-Soviet conflict that had intensified following Stalin's death reached its zenith: China invaded Damansky Island in 1969 but received a painful counterattack from the Russian army, and a terrified China approached Japan and the United States. The strategic environment in the western Pacific front was stable; Japan's acquisition of nuclear weapons hardly made any sense. The US military also withdrew its nuclear weapons from Okinawa and the Korean Peninsula.

Today, however, China has markedly increased its nuclear and conventional arsenal, beginning to seriously consider the armed annexation of Taiwan. CIA Director Burns testified earlier this year that the Chinese leadership issued instructions to finish military preparations to that end by 2027.

Abstract nuclear strategy theories serve only in academe. Nuclear weapons are so devastating as to kill millions, but, after all, they are weapons. The use of nuclear weapons varies depending on specific war scenarios: in what terrain, by what countries, under what leaders, and for what interests actors are fighting. China and North Korea may have their nuclear doctrines. The Japanese government currently lacks the necessary measures to address the nuclear threat from those countries.

What Japan must first prepare for is a Taiwan war. The United States still adheres to a policy of ambiguity and has no intention of deterring a Taiwan contingency with nuclear weapons. Taiwan became a symbol of freedom in Asia thanks to the democratization led by President Lee Teng-hui. The United States will be sure to fight for Taiwan. The US Department of Defense is steadily making preparations based on the Taiwan Relations Act. In the US Congress, Republican conservatives, who traditionally support Taiwan, and left-wing Democrats, who have been increasingly anti-Beijing, are expressing their support for Taiwan.

However, the United States has no intention of putting Taiwan under its nuclear umbrella. Uncertainty surrounds how the United States intends to handle nuclear parity with Russia and China, the two main nuclear powers. China, which still lags behind the United States in nuclear warheads, has not yet joined any nuclear arms control and disarmament framework such as the New START Treaty between the United States and Russia. The US nuclear strategy regarding Taiwan is flawed in many respects, which increases the likelihood of a conflict.

If a Taiwan war happened, would China use nuclear blackmail against Japan? Or would it resort to nuclear attacks on Japan? What should Japan do to deter them? These are the main points in nuclear deterrence theory that Japan should contemplate.

In the event of a Taiwan war, there will be three options for Japan: (1) continue to provide bases for US forces under Article 6 of the Japan-US Security Treaty, (2) provide logistical support for US forces following the Law Concerning Measures to Ensure the Peace and Security of Japan in Situations that Will Have an Important Influence on Japan's Peace and Security, or (3) declare an existential crisis and exercise its right of collective self-defense. The US military could not fight a Taiwan war without involving Japan. It would not be too difficult for China to paralyze Japan through a missile saturation attack or cyber attack on US military bases, JSDF bases, and critical infrastructure on the Japanese mainland. Strategically, this would not be a sensible option for China because it would direct the military might of the Japan-US alliance against China.

China produced the famous strategist Sun Tzu, whose precept is: "To fight and conquer in all your battles is not supreme excellence; supreme excellence consists in breaking the enemy's resistance without fighting." The way to win without fighting Japan is to horrify the Japanese people with nuclear blackmail, blow up the cabinet, and force Japan to leave from the front line.

At that juncture, Japan would confront the problem of how to manage the "sacrificial pawn psychology" likely to obsess the Japanese side, as was the case of Germany during the Cold War. This is a problem that Japan should bring up to the United States. A probable answer Japan could extract from the United States would be as follows: "The United States still possesses thousands of nuclear warheads; we outperform China in comprehensive strength in areas other than nuclear weapons as well, such as cyberspace, outer space, and submarine warfare. We have many allies on our side. Even if war breaks out, we will surely win. Trust us and reject China's nuclear blackmail."

If the United States and China were in a hair-trigger situation in which they would immediately launch an all-out nuclear war, the above answer would sound persuasive. However, a Taiwan war is no more than a localized war. Even if China employs nuclear weapons, there is no guarantee that the United States will retaliate with nuclear weapons. That said, if Tokyo were nuked, the United States would probably counterattack with nuclear weapons. But a demonstrative nuclear strike against a JSDF base on a remote island would not warrant a US nuclear response; the United States would rather choose a way to win a Taiwan war while avoiding the risk of a US-China nuclear war to the maximum extent. This is the real logic of war. An allied country to suffer atomic attacks would seek nuclear retaliation from the United States, but feelings of vengeance have nothing to do with a winning formula. The objective of war is a victory from beginning to end.

Then, it is natural for Japan, like Germany, to doubt that if a localized Taiwan war grew into a nuclear war at China's initiative, Japan might be obliged to play the role of a sacrificial pawn. Thus, the psychological gap is born between a nuclear and a non-nuclear state in a nuclear alliance. What excuse could the Japanese government offer to its citizens?

The Japanese government should not be satisfied with the US nuclear umbrella alone. As a signatory to the Nuclear Non-Proliferation Treaty (NPT), Japan is not in a position to independently develop nuclear weapons. However, we should remember this. When the United States pressed Japan to join the NPT, its hidden motive was to prevent Japan's nuclear armament. To that end, the United States was considering deploying US nuclear weapons in Japan, as in the case of Germany. Were it not for the No. 5 Fukuryu Maru Incident, this might have been realized but did not come true. Pragmatic politicians like the then still young Shintaro Ishihara raised their voices, asking if Japan should abandon its nuclear option. The Japanese government extracted from the US government the guarantee of the nuclear umbrella. From the US perspective, it was a legitimate request on the Japanese side.

Since Japan renounced the production and possession of nuclear weapons, it has the right to demand that the US nuclear umbrella should be flawless. Then, what should be done to achieve this?

First, ensuring the complete effectiveness of the US nuclear deterrent is crucial. Within the United States, certain groups of anti-nuclear lobbyists allied with left-wing Democrats. Unfortunately, some militant activists sometimes prioritize their political advocacy over the security of allies.

The no-first-use of nuclear weapons is another example. President Obama, who received the Nobel Peace Prize for his push for a nuclear-free world, became impatient with the lack of results in the final days of his administration; then, he came up with the idea of no-first-use of nuclear weapons. Reportedly, the reaction of US allies, including Japan, was chilly. President Obama's prestige was undermined after the Crimean Peninsula was seized without resistance by Russia. Many were concerned that if President Obama said America would not use nuclear weapons first, countries with superior conventional forces might start wars in different theaters. Obama's proposal could have given a wrong message to the burgeoning Chinese military establishment. Fortunately, Obama's no-first-use of nuclear weapons policy was not adopted.

Second is the redeployment of sea-based tactical nuclear weapons such as nuclear Tomahawks. The United States removed all naval tactical nuclear weapons after the Cold War ended. It also banned the deployment of ground-based medium-range missiles until the expiration of the INF Treaty. In the meantime, China and North Korea increased their medium-range missiles at will. Some of them are mounted with nuclear warheads. China has acquired an asymmetrical capability—intermediate-range missiles—over the Japan-US-Japan alliance.

The responsibility rests with Japan to fill the conventional missile gap. The Kishida administration has said it will begin with purchasing 400 Tomahawks, but this is a "stopgap" measure. The administration must extend the flight range of Type 12 surface-to-surface missiles so that they can be launched from land, sea, and air platforms and increase their number to several thousand. China is said to have 2,000 missiles capable of reaching Japan. That number will continue to grow.

It is the strong who deter the weak, not the reverse. Deterrence works only when a strategic stance is established at every stage in a conflict to guarantee that any missile launched will be met with one in return. Japan cannot do this alone; it must work with the United States to build up a ladder of deterrence from conventional to nuclear forces. The absence of a counterattack capability (intermediate-range missiles) on the Japanese side is a crack in the deterrence bulwark of the Japan-US alliance. It is Japan's responsibility to fix it.

What about nuclear weapons? Should US tactical nuclear weapons be brought into Japan, they should be submarine-based nukes for second-strike use. Japan has no land borders with any country; it is immune from being overrun by massive tank corps. Japan has only to possess second-strike nuclear weapons to counter the enemy's nuclear attacks by firing back. If sea-based tactical nuclear weapons were deployed in the waters near Japan, China would believe that if it nukes Japan, those sea-based tactical nuclear weapons will likely, almost surely, be used in retaliation, if not going so far as to employ the US strategic nuclear weapons.

The nuclear Tomahawk was originally developed as a deterrent to protect the US Carrier Strike Group from a Russian nuclear attack. Japan should have the United States declare the revival of the decommissioned weapon and its potential use in retaliation for nuclear strikes against regional allies. This would send a message to China and, at the same time, be instrumental to reassure the Japanese people. As a result, the risk of political disintegration of the Japan-US alliance due to China's nuclear blackmail would diminish a great deal.

Nobukatsu Kanehara is Visiting Professor at Doshisha University.

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