PROGRAM ON GLOBAL SECURITY DISARMAMENT

Issue Brief 2

WILL JAPAN KEEP RENOUNCING NUCLEAR WEAPONS IN THE COMING CENTURY?

LESSONS FROM THE 1960’S TO DETER THE DECISION TO “GO NUCLEAR”

August 2000 Version 

This issue brief was written by Masakatsu Ota, Fulbright Research Fellow.

Will Japan continue to renounce nuclear weapons and hold fast to its unique but ambiguous three non-nuclear principles – not to produce, not to possess and not to allow entry of nuclear weapons into its territory – in the twenty-first century? Historical analyses of the 1960s, when military-sensitive Japan faced its most tumultuous period and suffered from serious political division about nuclear and security issues, suggest that the answer, most likely, is yes. 

Recently discovered documents have shed light upon one particularly symbolic event during that era – the failure of Japan's most influential politician to overcome his nation’s unique phenomenon, the so-called “nuclear allergy.” The allergy has its origins in the memory of Hiroshima and Nagasaki more than half a century ago, but its lingering power was still strong enough to deprive a Japanese cabinet member of his post in the 1990s.

Even with its high standards in science, technology and its global economic power, the social trauma caused by the tragedies of the past makes it almost impossible for this nation to "go nuclear" without a fundamental change in its nature. And it is also true that this nuclear allergy has been functioning as an effective deterrent to any Japanese military resurrection.

Prime Minister's "Common Sense"

"If Chicoms [Chinese Communists] had nuclear weapons, the Japanese also should have them."

According to a declassified State Department document, in January 1965 Eisaku Sato, the newly elected Prime Minister of Japan, made the above statement during his first meeting with President Lyndon B. Johnson at the White House. Though he explained that his comment was an "individual” opinion, this public statement shocked the Johnson administration. Prior to this summit meeting, the American Ambassador in Tokyo, Edwin Reischauer privately recorded that Sato had indicated that "he [Sato] considers it only common sense for Japan to have nuclear weapons." Furthermore, Sato insisted that "Japanese public opinion will not permit this at present but [he] believes that the public, especially the younger generation, can be ‘educated’." After the summit meeting, Johnson, a strong advocate of an international nuclear control regime, made persuading Japan to sign the Nuclear Non-Proliferation Treaty (NPT) one of his top diplomatic priorities.¹

Since the middle of the 1960s, some Japanese politicians and scientists made it clear that the option to develop nuclear weapons exists for Japan. For instance, in October 1969, Finance Minister Takeo Fukuda, who was one of the most faithful of Sato's aides and who was later to become Prime Minister, stressed to Assistant Secretary of State Marshal Green that "Japan could develop nuclear weapons quite easily." On the other hand, Fukuda clearly denied the probability of the exercise of that Japanese nuclear option.² Also, in the early 1970s, Ryukichi Imai, an influential opinion leader in the Japanese nuclear industry and former Japanese Ambassador to the UN Conference on Disarmament, wrote that Japan would be able to build "nuclear weapons in minus two years."³

During World War II, the Japanese military establishment carried forward secret plans to develop its own atomic bomb. Two separate plans were simultaneously developed, which since the end of the war have become publicly known as the "Ni" and "F" projects. The former was undertaken by the army with a strong commitment from the nation's foremost physicist, Dr. Yoshio Nishina, whose last name was shortened to become the project's nickname. "F", meaning "fission", was the navy's clandestine project, which was supported by Kyoto Imperial University.⁴ In addition to those projects, one former official of the Japanese Defense Agency who had been in charge of military science during the war wrote in 1958 that the army had tried to develop a "homing device" which could be applied into a missile targeting system. He also pointed out that Japan had begun researching its own missile rocket technology in the mid-1950s.⁵

After losing the war, every one of Japan's covert scientific armament projects – atomic, chemical, biological and so on – was abolished by the Allied Powers. Although the Japanese A-bomb project was rather small, had a low priority for its leaders, and was handicapped by material shortages, the mere fact that Japan had already started developing its own nuclear weapon and primitive delivery measures meant that its technical potential and will had to be taken seriously. In June 1964, the State Department made an astonishing estimate about feasibility of Japanese nuclear weapons. The policy paper signed by then-Secretary Dean Rusk asserted with little ambiguity that, “if it decided now to embark on a nuclear weapons program, Japan could probably have its first nuclear device in five or six years and its first weapons deliverable by aircraft a year or so later; it could probably develop 1,000-mile missiles in about the same time, and compatible fission warheads for such missiles by 1970.”^[6]

Today it is not clear how many days Japan would need to manufacture its own nuclear weapon. But after having conquered many diverse aspects of peaceful nuclear power and having succeeded in launching domestically created rockets, Japan could presumably easily become a nuclear power much faster than Imai's 30-year-ago insistence of "two years." And its independent delivery system could be completed skillfully beyond the pace of the old State Department’s estimate. Noting Japan's huge stockpiles of reprocessed plutonium from both its own pilot plant and from energy contracts with British and France, one specialist concluded “emergency capability nuclear weapons could be deployed by Japan within a few months of the decision to produce them.”^[7]

Political Turmoil in 1960

So why has Japan not "gone nuclear," and why will it not in the future? A key to the answer is in analysis of historical events during the 1960s. This critical decade decisively influenced the future course of action of the first nation to be victimized by atomic bombs.

After the outbreak of the Korean War in 1950, the United States began to pressure Japan to take remilitarization procedures to provide for its own defense. But then Prime Minister Shigeru Yoshida initially rejected this idea, citing Article IX of the Japanese constitution that prohibited not only taking any military actions but also building military forces except for its self-defense. Yoshida thought his nation was too poor and weak to undertake remilitarization, which would entail costly procurement and a drain on its scarce manpower. So he concluded the best decision for Japan was to take advantage of its peaceful constitution provided by the United States, pour all of its resources into economic recovery, and postpone large-scale rearmament.^[8]

Thanks to the Prime Minister's political belief that specialists later dubbed the "Yoshida Doctrine," Japan achieved an unprecedented physical recovery at a swift pace and grew to be the second largest economic power in the free world by the late 1960s.^[9] This strategy of giving a priority to economics over the military added to the domestic pacifism among the entire nation and accelerated the anti-military mood caused by the devastation of the last war. This emphasis on economics added to the effect that the double tragedy in Hiroshima and Nagasaki had in creating Japan's "nuclear allergy."

Domestic political factors added some complexity to the general picture. Since the middle of the 1950s, the Japan Socialist Party (JSP) had maintained a second position behind the ruling Liberal Democratic Party (LDP) in the Diet. A key policy of this perpetual leading minority party was an emphatic anti-war stance, characterized by its political slogan "non-remilitarization and neutrality" which the JSP tried to inject into the political debate and the nation as a whole. During the 1960s, the JSP kept approximately one-third of Diet seats with strong support from labor unions and peace activists.^[10] As a result, the LDP was compelled to pay vigilant attention to JSP movements and to deal prudently with sensitive issues such as defense and nuclear weapons, in order to prevent gains by its rival.

This general pacifist "military allergy" was at its peak in 1960 when then Prime Minister Nobuske Kishi tried to revitalize the US-Japan Security Treaty and have it ratified in the Diet. Kishi, who was the former minister of the wartime Tojo cabinet and who wasan elder brother of Sato, had a conservative philosophy toward national defense and stated on some occasions that the possession of nuclear weapons for self-defense would not be unconstitutional.^[11]

Kishi reviewed several points of the 1951 version of the treaty and started renegotiations in 1957. His goal was to reinforce the US security guarantee for Japan, as well as to rectify what he saw as the demeaning features of the earlier agreement, such as the provision that allowed the United States to intervene in any Japanese internal disorder.^[12]

During the Diet session on ratification of the US-Japan Security Treaty in May 1960, ardent anti-treaty movements caused political turmoil. Protesting citizens surrounded the Diet building and 500 policemen had to forcibly remove opposition party Diet members from the Lower House so that the LDP could force through the vote. In June, more than 5 million workers participated in a strike to demonstrate their objections to the agreement. On top of that, these domestic upheavals forced President Dwight Eisenhower to cancel his visit to Japan, which was scheduled to commemorate a new era of US-Japanese security relations. Kishi himself paid his political price by resigning the top cabinet post in July, leaving heavy frustrations and an increasing anti-militarist trend in the public.^[13]

Sato's "Educational" Campaign

Hayato Ikeda, Kishi’s successor, evaded contentious agendas and put his priority on economic development after his inauguration. As one of the most faithful followers of the Yoshida Doctrine, he advocated doubling workers’ incomes in a decade and tried to create a reconciliatory environment in the Diet during his four-year tenure.

After the resignation of the moderate Ikeda cabinet in November 1964, Kishi's younger brother, Eisaku Sato, was elected President of the LDP, which automatically made him the Prime Minister. Before taking office, he made one significant political pledge that his predecessors, including his political mentor Yoshida, had never mentioned before publicly — he clearly promised his nation the reversion of the status of Okinawa, which was still under the administration of the United States.^[14]

Only two months after his inauguration, Sato went to the United States and met President Johnson. At this first meeting, Sato explained his great concern about the recent explosion of a nuclear device by the Chinese Communists and sought a credible guarantee of US nuclear deterrence. At the same time, he expressed his conservative and traditional view of self-defense by leaking his "common sense" declaration about Japanese nuclear potential. He continually emphasized not only Japanese residual sovereignty over Okinawa, but also on the importance of the US military installations on the islands in the context of the Vietnam War, which was Johnson's first priority.^[15]

After this meeting, he took a first step toward achieving his ultimate political aim. Every procedure and decision he would choose seemed to cater to the taste of the United States. Sato knew well that the reversion would be a difficult decision for Johnson to make. It was so difficult, Sato acknowledged, because nuclear weapons existed on the soil of Okinawa, which were held in constant readiness for a possible counter-offense against the Soviet Union and China.^[16]

According to the recently declassified US document, "History of the Custody and Deployment of Nuclear Weapons: July 1945 through September 1977," a wide variety of nuclear weapons and delivery systems began being deployed in the Pacific region in the middle of the 1950s. At the end of the Eisenhower administration, US nuclear deployments in the Pacific totaled approximately 1,600 weapons. About 800 of those were located at the Kadena Airbase, on Okinawa. And in 1967 when the war situation in Vietnam was intensified at the highest point, the United States stored more than 1,200 weapons.^[17]

Even though past Japanese cabinets had never officially confirmed the existence of nuclear weapons on the islands, it was easy for Sato to predict that the negotiation process would be arduous and difficult because the American determination to retain nuclear weapons on Okinawa seemed unshakable and unchangeable. At the second meeting with Johnson in November 1967, Sato faced US congressional leaders and military officials who were determined to continue the free use of military bases in Okinawa, which would of course include nuclear storage on its soil. He concluded that in order to realize his pledge to have Okinawa returned he would need more political leverage to gain support from the United States.^[18]

This strategic calculation seemed to suggest two potential solutions. One was to placate the United States by increasing his support for US foreign policies, especially the ongoing war in Vietnam. The other was to launch an "educational" campaign to raise the "defense consciousness" of the Japanese public, with the ultimate goal to overcome its nuclear allergy.^[19] To be successful, this campaign would have to convince the public to accept the storage of nuclear weapons on Okinawa, even though Diet minorities (including the JSP) and public opinion in Okinawa and in Japan vehemently rejected it.^[20]

To achieve the former, Sato reworked the draft for his speech at the National Press Club that was presented in Washington during the summit meeting in November 1967. Sato emphasized his clear support of US policy in Vietnam. This delighted Johnson, who praised Sato as a cooperative Asian leader.^[21]

Concerning his "educational" campaign, in January 1968, Sato allowed the first port-visit by the US nuclear-powered aircraft carrier (NPSS) USS Enterprise into Sasebo, the suburban US Navy base close to Nagasaki. Sato made this decision in spite of huge resistance not only from opposition parties and labor unions but also from moderate intellectuals, who suspected the existence of nuclear weapons aboard the ship. He did so because he believed that the NPSS visits were “matter of course in view of Japan’s obligation under [the] US-Japan security treaty."^[22] This historical visit paved the way for future visits by other NPSS vessels. And the Japanese government chose not to note whether nuclear weapons were on board, taking advantage of the US basic nuclear policy, neither confirming nor denying the existence of nuclear weapons (NCND).^[23] One memorandum for President Johnson implicitly praised Sato’s firm stance by saying, ”the Japanese had plenty of opportunity to ask for postponement or cancellation, but did not.”^[24]

Sato's domestic political base, the Diet majority LDP, helped his campaign by presenting a new "Action Plan" program that stressed the LDP’s support for the “democratic” order. The Action Plan attributed the decline of public order to left-wing propaganda and appealed for a rejuvenation of the national spirit with patriotic slogans like "love of homeland," "national spirit" and "defense consciousness." At the same time, the Education Minister proposed reforming the educational curriculum so as to incorporate national defense issues in primary-school syllabi and instill a sense of national pride.^[25]

On the other hand, Sato understood the importance of defusing public frustration and opposition to his right-tilt and pro-American policy. Right after returning from the Washington meeting, he officially declared the three non-nuclear principles at the Diet session in December 1967. Though this ostensibly pacific policy was one of the main reasons that he was awarded the Nobel Peace Prize, it was based on the premise that Japan should continue to rely on the nuclear umbrella provided by the United States.^[26] His superficial anti-nuclear stand is easily proved by another disclosure of his real intention. In January 1969, Sato said to then-Ambassador to Tokyo U. Alexis Johnson that “GOJ’s (Government of Japan) ‘three non-nuclear principles were ‘nonsense’.”^[27]

The hidden strategy behind Sato’s pacific declaration still remains to be researched. But it is certainly possible that one of his purposes was to dissolve US skepticism about the Japanese nuclear option suggested by Sato at the meeting with Johnson in 1965.Right after the summit meeting, the President’s "Task Force on Nuclear Proliferation," which was led by former Deputy Secretary of Defense Roswell Gilpatrick, recommended that Johnson “bring strong pressure” on Japan to take part in a new non-proliferation agreement.^[28] Also at the 1967 summit, the United States tried to put specific words into the Johnson-Sato Joint Communiqué that would guarantee a Japanese signature on the NPT.^[29] Sato seemed to be trying to defuse this US concern and head off future domestic criticism that his "educational" campaign might cause.

Failure of Sato’s Campaign

Despite a variety of efforts by Sato and the LDP, the “educational” campaign was much less successful than expected.

In February 1968, when it became public that B-52s stationed in Okinawa were participating in the war in Vietnam, strong vocal protests broke out on the islands as well as on the Japanese mainland. One State Department official in charge of the Japanese section wrote that, "If he [Sato] fails to reflect the Okinawa protests in approaches to us, he will be the target of a major political attack as a 'tool' of the Americans. Needless to say, Sato's plans for gradually bringing the public around to realistic security policies could at least be set back."^[30] Furthermore, in November a B-52 crashed at Kadena Airbase. Its function as a carrier of nuclear weapons increased the fear of people in Okinawa, triggering heavy protests that demanded the removal of B-52s from Kadena. Influential labor unions in Okinawa put the Sato government into another predicament by threatening to go on a general strike until the B-52s were withdrawn and visits by nuclear submarines were suspended.^[31]

The result of the first direct public election of Chief Executive of Government of Ryukyu Islands was also shocking and damaging for Sato and US authorities. With wide support from opposition parties as well as labor and teachers’ unions in Okinawa, Chobyo Yara defeated the LDP-backed conservative candidate. During his election campaign, Yara criticized Sato’s pro-American reversion initiative. Yara's victory must have reminded Tokyo and Washington of the strong anti-war and anti-nuclear attitudes among the people of Okinawa. Sato recorded in his diary on Election Day, November 11, 1968 that, “To my regret, Nishime [the candidate LDP supported] has lost. The reversion matter gets somewhat more difficult, doesn’t it.”^[32]Sato's "educational" campaign for the future Japanese territory had failed miserably.

On the mainland, the "nuclear allergy" had hardly disappeared. On May 6, 1968, “above-normal” amounts of radiation were detected in water and air samples at Sasebo Harbor, where the US nuclear-powered submarine SSN Swordfish was berthed. The Japanese Science and Technology Agency (STA) monitored the environment again in the evening of the same day and found nothing abnormal. Since US officials insisted that the Swordfish did not discharge its used water, the Japanese Foreign Ministry and STA decided that “whatever the cause, the original abnormal readings were in no way related to operation of Swordfish.” Also at this early stage, STA speculated that the cause was “heavy radar equipment [from other ships] in the vicinity which was beamed at the monitoring boat and might have had some effects on the instruments.”^[33]

The United States tried to hide all data dealing with the water and air samples, but the Japanese government made the results of the first tests public, causing a flood of media coverage and fanning the flames of public distrust. Though both countries quickly decided to cancel the next planned SSN visit in order to decrease public apprehension, skeptical front-page coverage did not die easily and opposition parties exploited this opportunity and demanded the cessation of future transits. After a Japanese investigation team ruled out the possibility of effects by the radar equipment of the other ship as the cause of the radiation, the media more emphatically presumed that the Swordfish was responsible for the contamination, although hard evidence was still lacking. Because of this hysteria, Tokyo took more than half a year to permit another SSN visit. Needless to say, the US government was disappointed with the handling by the Japanese side and recognized the deep roots of the "nuclear allergy."^[34]

Reflecting this “Swordfish incident,” the US Embassy in Tokyo sent a rather astonishing and disturbing message to Washington in March 1969: 

“The plain fact as we see it is that Japan is truly unique as regards NPW [Nuclear-Powered Vessels] visits, being the only country in the world with this particular combination of generally leftist scientific competence, considerable public ignorance about nuclear facts of life, powerful and mischievous-minded press and latent public hysteria about everything that can be labeled military-nuclear. In nutshell, nobody else in world is as lunatic about these matters as [the] Japanese…”^[35]

The Lesson: Exercising the Nuclear Option = Political Suicide

The strength of Japan’s "nuclear allergy" was eloquently shown by the unsuccessful challenge by one of the most defense-conscious and nationalistic politicians, Eisaku Sato. After his failure, he finally achieved his desperate political pledge, the reversion of Okinawa, without nuclear weapons in 1972. That meant his three non-nuclear principles had to be applied to post-reversion US bases in Okinawa. By the end of 1972, all US nuclear weapons had been withdrawn from Okinawa.^[36] Even though some details of the negotiation process between Sato and the US counterparts are still unknown, Sato’s efforts toward nuclear-free Okinawa is thought to be affected by the reality of his nuclear-phobic country, which was clearly shown by the unsuccessful result of his “educational” campaign.^[37]

Since the end of the Cold War, the Japanese left wing has waned in influence, and demonstrations organized by them have gradually decreased. But most of the major press still covers the annual commemorations of Hiroshima and Nagasaki on their front-pages. Even inside the domestic political arena, neither the majority LDP nor the biggest minority Democrat Party has ever announced its support for the development of Japanese nuclear weapons, nor storage of US weapons on their soil. Most politicians and decision-makers believe the US nuclear deterrent is sufficient to protect Japan, and is a less expensive option than developing and maintaining their own nuclear weapons.^[38] But there is also another reason.

In October 1999, then Prime Minister Keizo Obuchi dismissed his newly appointed Vice Defense Minister, Shingo Nishimura, after Nishimura made some controversial comments on nuclear weapons. In a popular Japanese magazine, he referred to Indian and Pakistani affairs and said, “Now that both countries have obtained nuclear [weapons], there will be no war between the two countries.” Furthermore, he continued, “What is most dangerous is a place with no nuclear weapons. Therefore, the Diet should consider the nation’s going nuclear,” causing a severe political backlash from opposition parties, which called for his replacement. Generally the Japanese media responded critically to his comments, forcing Obuchi to assure the nation that his government thoroughly holds fast to Sato’s three non-nuclear principles.^[39] Nishimura’s comments were made with a crisis on the Korean Peninsula in mind, which of course is a quite plausible scenario. But even after North Korea’s long-range missile passed over its territory in 1998, public opinion in Japan never showed strong support for an independent nuclear option.^[40]

This recent political confusion provides further evidence for the hypothesis that Japan will not go nuclear in the future. Since Sato’s experiences with his “educational” campaign, it has become the conventional wisdom among Japanese leaders that challenging the “nuclear allergy” is akin to political suicide.

I would like to express my most gratitude to Dr. Natalie Goldring, Executive Director of the Program on General Disarmament at the University of Maryland, for her professional instructions and gracious moral supports. Also, I owe Mr. Christopher Fettweis, the senior program staff, who helped editing this piece with his skilful talent and warm friendship. Finally, I want to appreciate a financial support for this research from the J. William Fulbright Foreign Scholarship Board.