113. Intelligence Note From the Director of the Bureau of Intelligence and Research (Hughes) to Secretary of State Rusk 1

No. 64


  • Japan and Nuclear Defense

The Japanese are being forced to come to grips with the problem of nuclear defense. For many years they have lived and prospered under the United States umbrella, without nuclear weapons on their soil and without having to discard their so-called “nuclear allergy.” Now, however, with 1) a decision to be made as to US base rights on Okinawa, 2) ABM's, NPSS's and the NPT being widely discussed, 3) the Chinese Communist nuclear missile threat fast becoming a reality, and 4) the broad question of Japan's future world role opening up, the Japanese are being pushed into making adjustments in their approach to the problem. The United States will have an important direct and indirect influence on Japanese defense decisions in the nuclear field.

Aversion to Nuclear Weapons Remains. Though the Japanese press has come increasingly to write openly and knowledgeably about nuclear weapons, the majority of the Japanese public still opposes Japanese acquisition of nuclear arms. (In a December 1967 poll 60% opposed and 14% favored Japan's having nuclear arms.) No responsible Japanese leader is prepared openly to advocate a change in government policy on this issue; there are reports that a few top conservatives believe Japan may have to or even should eventually acquire them, but there is no desire for these arms now. (Conservative leaders would like to reduce the “nuclear allergy,” however, in case it becomes necessary for Japan to permit the introduction of or to acquire nuclear weapons.) Illustrative of the prevailing attitudes, during the debate on Okinawa and defense at the December extraordinary Diet session following Prime Minister Sato's visit to the United States, the opposition parties played on the aversion to nuclear arms by alleging that the government was seeking an opening wedge to bring these weapons into Japan. Sato felt impelled to reaffirm repeatedly as government policy the so-called “three nuclear principles”—no Japanese manufacture, no Japanese possession, and no introduction into Japan of nuclear weapons. He said Japan would rely on the US nuclear deterrent [Page 259]and deferred any decision on the status of US bases in Okinawa to the future.

Okinawa Reversion May Force Decision on Introduction of US Weapons. Nevertheless, pressures for reversion of Okinawa are forcing the government toward a decision on whether to permit US nuclear weapons on Japanese soil. Sato has committed himself to achieving within two or three years a timetable for the reversion of Okinawa. Although he has said that the question of US base rights can be resolved afterwards, it seems clear that the Japanese will have to settle this issue before they can formulate a meaningful position on a timetable, unless, of course, the United States decides nuclear weapons on Okinawa are no longer necessary or desirable. In practical terms, it would probably be impossible for the Japanese Government to finesse the issue by legalistic stratagems, such as not assuming administrative jurisdiction over the territory occupied by US installations; the opposition would have good grounds for charging duplicity and evasion. From the way the debate has gone, there is good reason to believe that Sato is using the problem to generate changes in public attitudes toward Japanese security needs and reduce the Japanese “nuclear allergy,” as the opposition has charged. This does not necessarily mean he would actually like to grant nuclear base rights to the United States, unless he had to in order to get Okinawa back.

Debate Spurred by NPT, ABM's and NPSS Visit. Debate over US nuclear-powered surface ship visits, anti-ballistic missile defenses, and the Nuclear Non-Proliferation Treaty has also drawn Japanese attention to the nuclear weapons question. The most significant concern raised by the Enterprise visit2 was, like the Okinawa base problem, the question of introduction of nuclear weapons into Japanese territory (waters in this case). Both the Prime Minister and Foreign Minister expressed as their conviction to Diet interpellators that the Enterprise would not bring nuclear-armed weapons into port.3 In their battles with the police, the student demonstrators apparently aroused some [Page 260]local public sympathy and drew press attention to their demands.4 The impact of their efforts on the Japanese populace as a whole, however, may be no more sustained than the impact of the earlier demonstrations against the visits by nuclear-powered submarines. The visit will, nevertheless, help to sharpen public debate on defense issues.

The Japanese reaction to the US ABM deployment decision,5 while it did not extend much beyond the comparatively small defense-interested community, revealed the high degree of interest and sophistication of Japanese experts and analysts in the field of nuclear defense. Discussions stimulated by the ABM decision covered the gamut, including the possibility of a future US-Soviet arms race, the credibility of the US deterrent, the potential of the Chinese Communist nuclear-missile threat, and whether Japan needed ABM's or not. A senior Foreign Ministry official, understood to be Vice Minister Ushiba, noted that ABM's were purely defensive weapons; as such, there would be no constitutional impediment to Japanese acquisition of ABM's. The possibility of Okinawa being used as an ABM base, either for antiballistic missiles or as a base for a sea-borne missile fleet, has also been raised.

The proposed Nuclear Non-Proliferation Treaty has caused the most profound soul-searching in Japan, as it has focused attention on Japan's future role in a world of nuclear-weapons and non-nuclear-weapons states. The Japanese know that they can acquire a nuclear-weapon capability as rapidly as any other non-weapons state, but thus far they have chosen to deny themselves this world status symbol, partly because of the “nuclear allergy,” partly on practical and partly on moral grounds, all of which are interrelated. The NPT, however, [Page 261]raises the possibility of permanent self denial together with a permanent second-class power status. It appears that the Japanese will rationalize themselves around this problem, by signing the treaty but still maintaining their long range options. They have already insisted that the treaty contain provisions for periodic review, that all states have equal rights in developing peaceful uses, and that the nuclear-weapons powers promise to work toward discarding their arms while still providing security for non-weapons states (despite the apparent contradiction between the latter two propositions). They are also continuing to push peaceful nuclear and space development. If it should become clear at some future date that Japan would have to go nuclear to maintain its position in the world, its capabilities for doing so would be fully developed.

China—Menace and Competitor. Japan's overriding concern is its relationship to its giant Asian neighbor, Communist China. The Japanese know that their future role in Asia is directly tied in with this relationship. While China remains militant and threatening, the Japanese must either rely on the United States for protection, develop their own defenses, or both. And even if Peking takes on a less menacing aspect, it will remain a rival with Japan for Asian influence and leadership. The fact that China is developing nuclear weapons and Japan is not is thus a basic element in Japanese soul-searching over the nuclear weapons question, and as China becomes more powerful, the pressures on Japan to compete or accommodate are bound to increase. Most signs indicate Japan intends to compete; at this stage, it hopes that US protection will be sufficient to permit it to do so without nuclear weapons.

US Policy a Key Factor. As in the past the United States will play a major role in influencing Japanese defense policy. The US has urged the Japanese government to encourage Japanese defense-consciousness and to improve Japanese conventional forces, thus strengthening the government's own belief that this is in Japan's best interests. US nuclear ship visits and the US stand on base rights in Okinawa have contributed to the leadership's campaign to reduce Japan's nuclear allergy. At this stage, however, Japan appears content to rely on the US nuclear deterrent, possibly supplemented by ABM protection.

Interest in nuclear questions seems likely to remain strong in Japan. Whether in the future the Japanese will eventually decide to permit introduction of nuclear weapons into Japan and/or to acquire them will depend to a large extent on what the United States does—whether the US discourages Japan from going nuclear and offers continued, credible protection or whether it encourages Japan to acquire weapons either by lessening the credibility of US protection or by urging the Japanese to produce or share weapons. The possibility of Japan moving in [Page 262]a “de Gaullist” direction seems less likely, given its exposed strategic position and its heavy dependence on US trade. Whatever happens, as the Japanese “nuclear allergy” weakens, either through US actions, Japanese actions, or simply with the passage of time, it seems certain that Japanese willingness to entertain the possibility of acquiring nuclear weapons, either in concert with the US or independently, will increase.

  1. Source: National Archives and Records Administration, RG 59, Central Files 1967–69, DEF 1 JAPAN. Secret; No Foreign Dissem; Limdis.
  2. The USS Enterprise arrived at Sasebo on January 19 and departed on January 23. U. Alexis Johnson sent the Department of State an in-depth account of the events leading up to and surrounding the ship's visit. (Airgram A–1098 from Tokyo, February 23; ibid., DEF 7 JAPAN–US) Also see U. Alexis Johnson, The Right Hand of Power, pp. 489–495, which provides a comprehensive overview of the event.
  3. Airgram A–834 from Tokyo, December 29, recounts the Diet discussion on nuclear weapons and the visit of the Enterprise. (National Archives and Records Administration, RG 59, Central Files 1967–69, DEF 7 JAPAN–US) The arrival of the Enterprise sparked subsequent discussion and examination in Tokyo and in Washington on the issue of the introduction of nuclear weapons into Japan under the provisions of the Security Treaty. Telegrams and memoranda on that issue are ibid.
  4. According to the Consulate in Fukuoka, the visit of the Enterprise brought “the largest congregation of leftist demonstrators, police and media in history of Sasebo,” but the presence of the warship “was primarily excuse for organized left to mount propaganda campaign against U.S.-Japan security ties and to build up own morale and organization.” Although the visit itself unfolded without incident, large-scale student demonstrations, some of which were marked by violent clashes between small groups of students and police, occurred while the ship was in port. (Telegram 30 from Fukuoka, January 22; National Archives and Records Administration, RG 59, Central Files 1967–69, DEF 7 JAPAN–US)
  5. In response to Japanese interest in ABM development, Sato and other high-level officials were informed in mid-January 1967 that the United States, although developing the missiles, had no plans to deploy ABMs. A change in that decision hinged on the success of discussions with the Soviet Union on limiting ABM deployments. (Telegram 120576 to Tokyo, January 18, 1967; telegram 5091 from Tokyo, January 19, 1967; and telegram 121730 to Tokyo, January 19, 1967; all ibid., DEF 12 US) Later that year, however, on September 15, 1967, the United States informed the Japanese of a limited ABM deployment within the United States to counter the future Chinese nuclear threat and increase the security of Asia. (Telegrams 37294, 37446, and 38357 to Tokyo, September 14, 14, and 15, 1967, respectively; ibid., DEF 1 US)