KGRI Working Papers
No.11

Reselecting Nuclear Policy:
Kennedy, Ikeda, and U.S.-Japanese Nuclear Relations, 1961-63

Version 1.0
July 2017

Masaki Sakamoto i
Supervisor: Prof. Kanji Akagi (Faculty of Law, Keio University)

Keio University Global Research Institute© Copyright 2017 Masaki Sakamoto
Ph.D. Student, Graduate School of Law, Keio Universityi

Mail: Masaki.sakamoto1988@gmail.com

<Summary>In the early 1960s, U.S.-Japanese nuclear relations were still unstable. For the United States, Japan
was an important ally to support its nuclear test-ban diplomacy while Japanese national security greatly
depended on the extended nuclear deterrence of the United States based on the U.S.-Japan Security
Pact. In Japan, however, as its economy and technology improved, conflicting opinions on its nuclear
policy emerged. Under these circumstances, Hayato Ikeda, assuming the office of the Prime Ministerof Japan in 1960, had to handle the relationship with the Kennedy administration over nuclear issues
very carefully. Drawing from new historical documents in the Japanese Diplomatic Archives, thispaper shows how U.S.-Japanese nuclear relations were developed in the early 1960s and how Prime
Minister Ikeda managed Japan's nuclear policy the unstable environment both within and outside Japanafter the political turbulence toward the end of the 1950s. While most of the previous studies view
Ikeda's nuclear policy as just following the footsteps of his predecessors, this paper argues that his
nuclear policy was very important in framing Japan's post-war nuclear policy.

1

<Table of Contents>

1.

1.

Introduction .................................................................................................................................. 2

2.

Japan and Nuclear Weapons after the Second World War .................................................... 4

3.

Ikeda's Visit to Washington DC, June 1961 .............................................................................. 6

4.

The Rise of "Nuclear-armed Japan" Arguments .................................................................... 10

5.

Partial Test Ban Treaty ............................................................................................................... 14

6.

Conclusion .................................................................................................................................. 18

Introduction
Japan is one of the countries that has historically maintained complicated stance toward nuclear
weapons. Japan is the sole country to have suffered nuclear attacks. The atomic bombings of Hiroshima
and Nagasaki in 1945 have made Japan a strong anti-nuclear weapons country, arguing for nuclear
abolition for many years in the United Nations General Assembly. On the other hand, it is also
inevitably true that Japan's post-World War II national security has highly depended on the U.S.'
extended nuclear deterrence. This contradictory stance, which is often mentioned as "Japan's nuclear
dilemma", has often split Japanese public opinion toward nuclear weapons.1
From this point of view, the early 1960s was much more important for the history of Japan's
nuclear policy than has ever been argued. The widespread demonstrations against U.S.-Japan. Security
Treaty at the end of the 1950s, which is also known as Anpo Toso, cast doubt on the situation in which
Japan's national security greatly depended on U.S.' "nuclear umbrella." As a result, in the early 1960s,
there were several types of challenges, both domestic and international, and choices for deciding on

1

After the Fukushima nuclear accident in March 2011, "Japan's nuclear dilemma" has been used withdifferent meanings in the context of the energy policy. "Japan's Nuclear Dilemma," Council on Foreign
Relations (CFR). https://www.cfr.org/interview/japans-nuclear-dilemma2Japan's nuclear policy. Under such an unstable situation, Japan's Prime Minister Hayato Ikeda had todeal with several problems related to nuclear weapons.
When discussing Ikeda administration from 1960 to 1964, the leading image is its economic-firstpolicy which was symbolized by the "Income Doubling Plan (Shotoku Baizo Keikaku)."2 In fact, mostof the previous studies on Ikeda administration have focused on its economic policy while paying little
attention to its national security policy.3 It is true that Ikeda, learning from the severe lesson of Anpo
Toso at the end of the 1950s, prioritized Japan's economic growth as a political goal to avoid further
confusion over how Japan should position itself in the Cold War confrontation. Many studies argue
that he was an "honor student of the Yoshida Doctrine", a strategy to concentrate on economic
development while depending on the security alliance with the United States in order to reconstructpost-war Japan's economy. They say that Ikeda faithfully followed the policy of his predecessor andlong-term mentor Shigeru Yoshida.4 Yet, it does not mean that he was focusing only on the economic
policy. In fact, some recent studies have revealed various aspects of his foreign policy.5 Among them,
Ikeda's nuclear policy awaits further study.

Strictly speaking, Ikeda's slogan was "Income Doubling Policy (Shotoku Baizo Seisaku)," and later, theEconomic Planning Agency of Ministry of Economy, Trade and Industry (METI) framed the "Income
Doubling Plan," which is widely known today. Though there was some difference between these two terms,
I generally use "Income Doubling Plan" in this paper. Nobuyuki Fujii, Ikeda Hayato: Shotoku Baizo de
Ikunda (Tokyo: Minerva Shobo, 2012), pp. 1-2.
3
Yumi Hiwatari, Sengo Seiji to Nichibei Kankei (Tokyo: Tokyo University Press, 1990), pp. 187-273;
Timothy P. Maga, "The new frontier and the new Japan: Kennedy, Ikeda, and the ‘end of US protectionism’,
1961–63" Diplomacy & Statecraft 5, issue. 2 (1994): pp. 371-393; Michael Schaller, Altered States: The
United States and Japan since the Occupation (Oxford: Oxford University Press, 1997), pp. 163-83;
Hayato; Takafusa Nakamura, "Ikeda Hayato: 'Keizai no Jidai' wo Tsukutta Otoko", Sengo Nihon no Saisho
Tachi edited by Akio Watanabe (Tokyo: Chuo Koron Shinsha, 2001), pp. 175-206; Fujii, Ikeda Hayato.
4
Qingxin Ken Wang, Hegemonic Cooperation and Conflict: Postwar Japan's Policy and the United States(Westport: Praeger, 2000), p. 136; Hiwatari, Sengo Seiji to Nichibei Kankei, pp. 187-273.
5Toshihiro Higuchi, "Kakujikken Mondai to Ikeda Gaiko," Ikeda Sato Seikenki no Nihon Gaiko, edited by
Sumio Hatano (Tokyo: Minerva Shobo, 2004), pp. 199-233; Yoshihide Soeya, Nihon no "Middle Power"
Gaiko: Sengo Nihon no Sentaku to Koso (Tokyo: Chikuma Shobo, 2005), pp. 81-98; Akira Kurosaki,
Kakuheiki to Nichibei KAnkei: America no Kakufukakusan Gaiko to Nihon no Sentaku, 1960-1976 (Tokyo:
Yushisha, 2006); Shingo Nakajima, Sengo Nihon no Boei Seisaku: "Yoshida Rosen" wo Meguru Seiji,
Gaiko, Gunji (Tokyo: Keio University Press, 2006), pp. 171-222; Kosuke Yoshitsugu, Ikeda Seikenki no
Nihon Gaiko to Reisen: Sengo Nihon Gaiko no Zahyojiku, 1960-1964 (Tokyo: Iwanami Shoten, 2009);
Hironao Suzuki, Ikeda Seiken to Kodoseichoki no Nihon Gaiko (Tokyo: Keio University Press, 2013). Nick
Kapur, "Mending the 'Broken Dialogue': U.S.-Japan Alliance Diplomacy in the Aftermath of the 1960
Security Treaty Crisis," Diplomatic History 41, no. 3 (2017): pp. 489-517.
32

Based on newly released document from the Diplomatic Archives of Japan, this paper examines
how the Ikeda administration worked on its nuclear policy and U.S.-Japan relationship in the early
1960s. Since the beginning of the post-war period in the 1940s, the United States has been the mostimportant partner of Japan's nuclear policy. It is almost impossible to discuss Japan's nuclear policy
without mentioning the role of the United States.
The analysis is broken up into four sections. Section two describes Japan's situation with regard
to nuclear weapons immediately after the Second World War. Section three explains how Ikeda's
disarmament policy faced troubles during the U.S.-Soviet confrontation over nuclear tests. Section
four looks at the rise of the "nuclear-armed Japan" argument within and outside the Japanese
government. Section five examines Japan's decision to participate in the Partial Test Ban Treaty(PTBT) and policy debates that accompanied it.

2.

Japan and Nuclear Weapons after the Second World War

After the defeat in the Second World War, Japan's research on atomic energy was severely
restricted by General Headquarters (GHQ). On September 22, 1945, General Douglas MacArthur
issued Directive No. 3 (also known as SCAPIN 47), which specifically prohibited "all research ordevelopment work which has as its object effecting mass separation of Uranium 235 from Uranium,or effecting mass separation of any other radio-actively unstable elements." 6 The restriction was
gradually eased as the United States changed its nuclear policy. After the failure of the Baruch Plan, aproposal that called for an international organization to regulate atomic energy, the United States atfirst tried to monopolize nuclear technology in order to prevent the proliferation of nuclear weapons.
Yet, the Soviet Union's first nuclear test in 1949 made the United States recognize that monopolizationof nuclear technology no longer worked. As a result, at the UN General Assembly on December 8,
6

SCAPIN-47: Directive no. 3, Office of the Supreme Commander 1945/09/22, SCA-1 R2, National Diet
Library Digital Collection. http://dl.ndl.go.jp/info:ndljp/pid/9885109
4

1953, President Dwight Eisenhower delivered the "Atoms for Peace" speech, and began to supply
atomic energy equipment and information with promises of peaceful use of uranium use for peacefulpurposes throughout the world.7 The program was also applied to Japan. In 1955, the two countries
concluded the U.S.- Japan Nuclear Cooperation Agreement. Along with the agreement, the Japanese
government enacted the Atomic Energy Basic Act in 1956, which provided the guidelines for nuclear
energy researches. However, even after such progress, militarization of nuclear energy was severely
restricted. Through technological cooperation and resource supply, the United States controlled Japan's
nuclear policy and did not allow it to conduct any nuclear energy research for military applications.
As nuclear weapons had become highly important in international security through the 1950s,
Japan was incorporated into the U.S. "nuclear umbrella." As George Kennan identified, the UnitedStates saw Japan as one of the world's five major centers of industrial power against Soviet expansion.8
Thus, it was essential for the U. S. Cold War strategy to set up a robust defense system including
nuclear weapons for Japan. Plus, in the U.S. nuclear deterrence strategy in East Asia, Okinawa was themost important base due to the limitations on the deployment of nuclear weapons in Mainland Japan.
In other words, the United States needed to incorporate Japan in its nuclear umbrella both to defend it
and to use it for its regional nuclear defense system9.
Such an environment allowed the Japanese government to be surprisingly indifferent, at least on
the surface, to the idea to acquire its own nuclear weapons. In fact, Japanese defense plans had nevermentioned nuclear weapons until the early 1970s. The Second Defense Build-up Plan, released in July
1961, only indirectly mentioned nuclear weapons by saying that "Japan builds up national defense
structure focusing on effective measures against limited intervention with conventional weapons under

Public Papers of the Presidents of the United States (PPPUS): Dwight D. Eisenhower, 1953 (Washington
D.C.: USGPO, 1960), pp. 813-22.
8
George F. Kennan, "Contemporary Problems of Foreign Policy," National War College, September 17,
1948, Box 299, Folder 12, George F. Kennan Papers, 1871-2005 (bulk 1950-2000), Princeton University
Library.
9
Masakatsu Ota, Nichibei "Kaku Mitsuyaku" no Zenbo (Tokyo: Chikuma Shobo, 2011), pp. 43-172.
7

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the U.S.-Japan Security Treaty."10 The reason for excluding the role of nuclear weapons in its defense
plan was two fold: First, Japanese officials were simply indifferent to the issue and, second, they tried
not to stimulate anti-nuclear sentiment among Japanese people. Anyway, at least until the 1960s there
was little discussion on military and defense issues in Japanese society, much less one on nuclear
defense capability.
On the other hand, successive Japanese governments has been spending enormous energy on
nuclear disarmament and test ban diplomacy since the middle 1950s. The atomic bombings ofHiroshima and Nagasaki in 1945 left a deep scar on Japanese society. In addition, the Japanese fishingboat Lucky Dragon Five (Daigo Fukuryu Maru) was exposed to nuclear fallout from the thermonuclear
weapon test conducted by the United States at Bikini Atoll on March 1, 1954. This accident kindled
an anti-nuclear movement in Japan.11 In August 1955, the first World Conference Against Atomic andHydrogen Bombs was held in Hiroshima. Pushed by the grass-roots movement, the Japanese
government also engaged in anti-nuclear activities. Particularly, the Japanese government showed its
strong interest in nuclear test ban agreement among the three nuclear states. Since joining the United
Nations in December 1956, in the U.N. General Assembly, Japan continued to commit to the problems
related to nuclear test.12

3.

Ikeda-Kennedy Meeting and Nuclear Test Resumption

When Japanese Prime Minister Ikeda assumed office in July 1960, his strategy toward the next
general election, which was supposed to be held in November, was to emphasize economic growthplan, which is well known as Income Doubling Plan. 13 The political dispute over the U.S.-Japan

Yoshitaka Sasaki, "Kaku Senryaku no Naka no Nihon," Kaku to Taiketsu Suru 20 Seiki (Tokyo: Iwanami
Shoten, 1999), edited by Yoshikazu Sakamoto, pp. 190-191.
11
Hiroki Sairenji, "Japan and Nuclear Test Ban Problems," International Relations, no. 136 (2004): pp. 3-4.
(Japanese)
12
Ibid., pp. 6-12.
13
Fujii, Ikeda Hayato.
106Security Treaty and the resignation of the former Prime Minister Nobusuke Kishi showed Ikeda thedanger and difficulty in openly dealing with national security problems, which apparently include
nuclear weapons' problems. Yet, it does not mean that Ikeda completely forgot issues related to nuclear
weapons. Rather, nuclear disarmament diplomacy was one of the most important subjects in therelationship between Japan and the United States.
On January 11, 1961, just before Kennedy assumed office, the Ikeda administration asked the U.S.
embassy for holding the U.S.-Japan summit meeting in Washington DC. 14 The U.S. government
welcomed this request and decided on the date for the meeting as March 3. Ikeda's visit to Washington
DC was mainly aimed at demonstrating "Equal Partnership" between the United States and Japan.15
For this purpose, Japanese officials thought that the discussion should focus on general issues in theinternational society rather than the issues related to the U.S.-Japan alliance because the latter would
inevitably make the power gap between the two states too obvious.16 In that sense, disarmament andarms control were appropriate issues.
On June 20, 1961, Ikeda visited Washington DC and saw John F. Kennedy for the first time. During
his three-day stay in Washington DC, Ikeda and Kennedy met three times. In the first meeting,Kennedy told Ikeda that the United States expected Japan to participate in the international
disarmament negotiation more actively. The United States was considering the participation ofcountries then not represented in the Ten-Nation Disarmament Committee and had Japan in mind as
one of those countries. 17 Kennedy, who had a bitter encounter with Khrushchev a few weeks
previously in Vienna, needed a partner country in his disarmament negotiation. 18 Plus, Kennedy
desired an expanding international role for Japan, particularly among non-European nations. "[The"Ikeda Sori Beika Homon ni Kansuru Hokokusho," August 1961, Homon Kankei Ikken Chosho "Beika
Homon Kiroku," A'152 10-3, Diplomatic Archives of the Ministry of Foreign Affairs of Japan (DAJ).
15
Schaller, Altered States, pp. 169-170.
16"Ikeda Sori Hobei Dai 1 Kai Uchiawase," April 17, 1961, Ikeda Sori Beika Homon Kankei Ikken 1961/6,
A'152 10-1, DAJ.
17
Memorandum from Robert H. Johnson to Rostow, "Prime Minister Ikeda's Visit," June 19, 1961, National
Security File (NSF), Japan, Box 123, John F. Kennedy Presidential Library (JFKL).
18
Higuchi, "Kakujikken Mondai to Ikeda Gaiko," pp. 207-9.
14

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United States should] encourage and assist Japan," one report prepared by U.S. official argued, "toexercise a moderating and constructive influence in the UN, …but avoid efforts to overidentify Japan
with Western positions to the extent that its usefulness and influence among Afro-Asians is undermined
and to this end accept occasional divergencies [sic.] of viewpoint."19 Kennedy administration regarded
Japan's unique position as useful to cooperatively proceed with their nuclear disarmament diplomacy.
Ikeda administration also recognized the importance of the cooperation between Japan and theUnited States over nuclear disarmament and arms control negotiation. In Tokyo, the Ministry ofForeign Affairs of Japan concluded that Japan should "positively participate in the negotiation to
improve Japan's international status." 20 This "international status" consideration reflected on two
aspects of Ikeda's policy. First, as Japanese economy recovered from the ashes of the Second World
War, participation in international society became the next important task for the government. Seeking
the U.S.-Japan "Equal Partnership" had risen in this political context. Also, since assuming office,Ikeda showed great interest in gaining membership in the OECD.21 To improve Japan's international
status was one of the important tasks toward achieving this goal. Second, as Ikeda intentionally focusedon economic policy to avert public interest from other issues such as military defense problems andthe Cold War conflict, he also tried to avert the attention of Japanese people from the narrow U.S.Japan relationship to the broad range of international relations. The field of nuclear disarmament andarms control, where Japanese government had spent great effort in the United Nations since the middle
1950s, was best fitted to achieve these aims.
Both President Kennedy and Prime Minister Ikeda recognized the urgent need for agreement on
nuclear test ban accompanied by effective inspection and control measures, agreeing that it is of crucial
importance not only for building cooperative bilateral relationships but also for world peace. They also
shared their conviction that renewed effort should be made in the direction of general disarmament.

"Guidelines for US Policy toward Japan," November 20, 1961, Digital National Security Archive (DNSA).
"Nihon no Gunshuku Kosho Sanka ni Tsuite," June 21, 1961, Kokuren Gunshuku Mondai, SB'223, DAJ.
21
Suzuki, Ikeda Seiken to Kodoseichoki no Nihon Gaiko.
19
20

8

Overall, the Ikeda-Kennedy summit meeting in June 1961 was a favorable start for the two new leaders
to coordinate their nuclear disarmament and arms control diplomacies.
However, the euphoria faded just a few months later when trouble began with the Soviet Union's
declaration of nuclear test resumption. When Khrushchev declared the resumption of nuclear tests on
August 31, 1961, Japan openly and harshly criticized the decision while understanding that the UnitedStates would also restart nuclear tests sooner or later.22 During the meeting with Ikeda in June 1961,
Kennedy told him that the United States might resume nuclear tests in the near future under the present
gridlock of test-ban negotiations with the Soviet Union.23 If the United States resumed nuclear tests,
then the criticism against nuclear test became a double-edged sword and Japan could not blindly blame
the Soviet Union. Therefore, the Japanese government repeatedly asked the U.S. government to inform
its allies of the resumption of nuclear tests well before the public announcement.
Kennedy at first tried to take full advantage of Russia's reckless unilateral action and leadinternational public opinion against Russia, but the hesitant and delayed reaction of the internationalsociety soon disappointed him. In addition, as Russia conducted nuclear tests at an unexpected highpace, growing concern in the government pressured Kennedy24. On September 5, Kennedy announced
the resumption of underground weapons testing.25
The news of U.S. resumption of nuclear tests was a great shock for Japan not because of theresumption itself but because of the lack of advance notice from the U.S. government. The
announcement came just when Japanese representatives had been preparing themselves for the United
Nations General Assembly to accuse the Soviet Union of resuming nuclear tests. Soon after hearing
the news, Chief Cabinet Secretary Masayoshi Ohira publicly commented that the Japanese government
was unconditionally opposed to any nuclear tests and hoped the United States would reconsider and

Higuchi, "Kakujikken Mondai to Ikeda Gaiko," pp. 210-213. Telegram from Washington to Tokyo,"Sori Hobei (Kakujikken Mondai) no Ken," June 20, 1961, Ikeda Sori Beika Homon Kankei Ikken 1961/6,
A'152 10-1, DAJ.
24
Editorial Note, August 31, 1961, Foreign Relations of United States (FRUS), 1961-63, Vol. VII(Washington D.C.: US Government Printing Office (USGPO), 1986), doc. 61.
25
National Security Action Memorandum No. 87, September 5, 1961, FRUS, 1961--63, Vol. VII, doc. 65.
922
23

hold back from resuming nuclear tests26. The next day, the Japanese government ordered Koichiro
Asakai, the ambassador to the United States, to hand a note verbale, which was the same document
handed to the Soviet Union to criticize the resumption of nuclear tests.27
The discommunication between the two governments was soon mended. When the United States
decided to announce the resumption of atmospheric nuclear tests in March 1962, it was only Ikeda andBritish Prime Minister Harold McMillan among the foreign leaders to whom Kennedy sent a personal
letter and explained the decision beforehand. Advised by the U.S. ambassador to Japan, Edwin O.
Reischauer, Kennedy recognized that this special treatment was necessary and effective to show Japan
his sincere attitude toward the cooperative relationship between the United States and Japan.28 While
the Japanese government publicly criticized the U.S. decision, such special treatment was certainly
enough to satisfy the Japanese government, which was seeking for the status of first-rate state after the
post-war restoration. The United States recognized both the importance of Japan for nuclear
disarmament policy and the importance of nuclear disarmament policy for Japan. For the United States,
the Japanese presence in the disarmament negotiation was important in terms of its historicalexperience and region. On the other hand, the United States, especially Walt Rostow, Kennedy's
National Security Advisor, also recognized that nuclear disarmament negotiation was a good field forJapan to show its commitment to international society and gain a reputation.29 It was desirable for theUnited States too that Japan made its presence felt and played a prominent role in the internationalsociety.

4.

The Rise of "Nuclear-armed Japan" Arguments

September 6, 1961, Yomiuri Shimbun.
September 7, 1961, Yomiuri Shimbun.
28
Washington told Reischauer: "At your discretion you may inform Ikeda that he and MacMillan only headsof government receiving advance notification this decision." Telegram from Washington to Tokyo, February
28, 1962, DNSA. Editorial Note, March 2, 1962, FRUS, 1961-63, Vol. VII, doc. 143. March 2, 1962,
Yomiuri Shimbun. Nick Kapur, "Mending the 'Broken Dialogue'," p. 508.
29
Memorandum from Robert H. Johnson to Rostow, "Prime Minister Ikeda's Visit," June 19, 1961, NSF,
Japan, Box 123, JFKL.
10
26
27

When Ikeda was energetically working on nuclear disarmament diplomacy there had risen"Nuclear-armed Japan" arguments inside and outside the government. There were several reasons forthese arguments drawing much attention at that time. First, economic and technological development
made Japan capable, at least if there was the U.S. support, of acquiring its own nuclear weapons.
Second, after Anpo Toso in the late 1950s, many people cast doubts on the situation in which Japan's
national security greatly depended on the U.S.' "nuclear umbrella." Finally, the international situation
surrounding nuclear weapons affected those people who claimed the need for nuclear development
plans for Japan. These factors made the idea realistic and likely to come true.
On June 21, 1962, during an informal conversation with U.S. embassy staff, Shinsaku Hogen,Director-General of Oua Kyoku (European and Oceanic Affairs Bureau), said that "he personally
thought Japan should eventually acquire its own nuclear weapons so as to bring more equality into
Soviet-Japanese relations and reduce the massive threat posed by Communist China's development of
a nuclear weapons capability." He believed that Japanese opinion would become more realistic andaccepting of the idea of national nuclear weapons in the near future. Though other participants ofJapanese Ministry of Foreign Affairs opposed Hogen's idea, he continued saying that it was a questionof national prestige and assurance in an age of "nuclear power politics."30 It was not the first time that
the Japanese government staff mentioned to the possibility of Japan's possession of nuclear weapons,but Hogen's comment is worth noting in that the government staff directly showed his interest inJapan's nuclear armament in front of the U.S. government staff. At that time in the National Diet, theSocialist Party argued that Japan should declare its nuclear demilitarization, an idea that had once
failed due to the disagreement with Liberal Democratic Party in the late 1950s31. Hogen's remark wentcompletely against that movement.
This "nuclear-armed Japan" argument was followed by Shigeru Yoshida, the former Prime
30
31

Telegram from Tokyo to Washington, June 21, 1962, DNSA.
June 4, 1962, Yomiuri Shimbun.
11

Minister and Ikeda's long-time mentor. In his speech at the America-Japan Society in July 1962,
Yoshida said that Japan should have the spirit and determination to acquire nuclear weapons when time
had come in order to develop U.S.-Japan friendship and to contribute to the world peace.32 Shingo
Nakajima argued that Yoshida's comment on Japan's nuclear armament implied his critical position
against Ikeda's nuclear disarmament diplomacy. 33 Although Yoshida had already retired and not
officially worked for the government, he still possessed unignorable power on the political scene.
Therefore, his affirmative stance toward Japan's nuclear armament created much more impact than thatof general retired politicians.34
U.S. policymakers also recognized that a part of the Japanese conservatives called for Japan's own
nuclear weapons, but their view on this trend was complex. As a premise, they never thought that Japan
would go nuclear at least in the near future. In September 1961, National Intelligence Estimate (NIE),"Likelihood and Consequences of the Development of Nuclear Capabilities of Free World Countries
Other than the US and UK," said that "[Japan] could have its first nuclear device in 5 or 6
years…However, antimilitary, particularly antinuclear, attitudes remain extremely strong among the
populace."35 Even after recognizing the rise of the "nuclear-armed Japan" argument, they still mademuch of the strong anti-nuclear feelings among Japanese people. For example, a report from U.S.
embassy in Japan on November 21, 1962, mentioning to Yoshida's speech in July 1962, reported that
"The fact that these remarks were considered quite daring, and the pains which Yoshida's supporters
took to keep the speech out of the major dailies must also be taken into account."36
Whether "nuclear-armed Japan" was favorable for the United States or not was also an arguable
point. Preventing the proliferation of nuclear weapons was one of the top priorities for the Kennedy
administration and they made little distinction between allies and adversaries on this matter. At the

Shigeru Yoshida, "U.S.-Japan Relations," The America-Japan Society Bulletin, 6, no. 1 (May-July, 1962).
Nakajima, Sengo Nihon no Boei Seisaku, pp. 200-3.
34
July 13, 1963, Asahi Shimbun.
35
National Intelligence Estimate (NIE): "Likelihood and Consequences of the Development of Nuclear
Capabilities of Free World Countries Other than the US and UK", September 21, 1961, DNSA.
36
Telegram from Tokyo to Washington, November 21, 1961, DNSA.
12
32
33

meeting with Ikeda at Hakone in November 1961, when Ikeda said that at least a minority, including
people in his own cabinet and party, considered it necessary for Japan to possess nuclear weapons,Secretary of State Dean Rusk made it clear that the United States was opposed to the proliferation of
nuclear powers.37 Plus, though the Kennedy administration desired a rapid and effective growth ofJapan's military capability to share its defense burden, it was only within the conventional forces. For
the United States, the rise of a "nuclear-armed Japan" argument was welcome only in the sense that it
implied a faint trend toward a greater acceptance of the realities of the world's strategic situation andpossibly the modest decline of anti-nuclear feelings in Japanese society. 38 On February 6, 1963,
Deputy Secretary of Defense Roswell L. Gilpatric visited Japan and stayed there for two days todiscuss defense matters between the United States and Japan. In the meeting with Ikeda, Gilpatric said
that the United States hoped that Japan would continue its defense build-up but that Japan's efforts
should be in conventional forces.39 Gilpatric thought that the most serious threat in East Asia was theaggression of Communist China with its enormous deployment of conventional forces and he hopedthat Japan played a more significant role in deterring it. In other words, Gilpatric never thought thatJapan should take the responsibility of nuclear deterrence.40
Whatever opinion Ikeda actually had on "nuclear-armed Japan" argument in his mind, publicly henever showed any support for it.41 It was only when he talked with Rusk at Hakone in November 1961
that he showed a slight interest in the idea of Japan's acquiring nuclear defense capability in front of
the U.S. official. In response to Rusk's comment that the United States was opposed to any nuclear
proliferation, Ikeda said that "he had not been thinking so much of Japan's going into the productionof nuclear weapons, but of the argument that the presence of nuclear weapons in Japan might be
Memcon, November 3, 1961, FRUS, 1961-63, Vol. XXII, doc. 346.
Telegram from Tokyo to Washington, November 21, 1961, DNSA.
39
Telegram from Tokyo to Washington: "Visit to Japan by the Honorable Roswell L. Gilpatric, Deputy
Secretary of Defense," February 20, 1963, DNSA. Memorandum from Gilpatric to President, February 8,
1963, FRUS, 1961-63, Vol. XXII, doc. 368.
40
Ibid.
41
In private, Ikeda several times showed his interest in "nuclear-armed Japan" idea. Yasuhiro Nakaseone,
Nakasone Yasuhiro ga Kataru Sengo Nihon Gaiko (Tokyo: Shincho sha, 2012), pp. 176-8; Masaya Ito,
Ikeda Hayato: Sono Sei to Shi (Tokyo: Shiseido, 1966), pp. 196-7.
37
38

13

necessary for its defense" and "he would be interested in learning more about the broader aspects of
the nuclear armaments question."42 Yet, that comment still remained within the range of a moderate
tone. Even when his long-term mentor Yoshida gave supportive comment on "nuclear-armed Japan,"the Prime Minister publicly disagreed with his idea.43 Ikeda rationally understood that the politicalrisk to touch nuclear issues was still too high under the then prevailing situation of Japanese public
opinions. Overall, due to the Prime Minister's cautious stance, the rise of "nuclear-armed Japan" didnot become mainstream in Ikeda administration.

5.

Partial Test Ban Treaty

In July 1963, after the tripartite negotiation among the representatives of the U.S., the U.K. andthe Soviet Union in Moscow, they finally reached an agreement over nuclear test ban.44 Partial Test
Ban Treaty (PTBT) prohibited all test detonations of nuclear weapons except for those conductedunderground. The treaty resulted from the long negotiation since the late 1950s, but in the short term,
many changes in international relations contributed to that outcome. The two most important factors
among them were the Cuban Missile Crisis and the Sino-Soviet split.
Kennedy thought that the number of PTBT participants was significantly important for threereasons. First, PTBT was the first nuclear arms control agreement of the Cold War and, therefore,
Kennedy hoped to make it look as magnificent as possible. In addition, the draft of PTBT was
originally agreed on by the three countries to regulate further atmospheric pollution, but consideringthat the treaty also aimed to prevent the proliferation of nuclear weapons by directly banningatmospheric tests, it was highly important to make as many countries as possible sign the treaty. Finally,
the number of PTBT participants was important to isolate and indirectly contain those that did not join

Memcon, November 3, 1961, FRUS, 1961-63, Vol. XXII, doc. 346.
July 20, 1962, New York Times.
44"Tripartite Communique on the Conclusion of the Moscow Test-Ban Negotiations," July 25, 1963,
Documents on Disarmament (DoD), 1963, (Washington D.C.: USGPO, 1964), pp. 249-250.
42
43

14

the treaty. Particularly, Kennedy was seriously concerned about the People's Republic of China's
nuclear weapon program and saw the rift between China and Soviet Union as a great chance to isolate
China.45 Actually, in the last part of the radio and television address on PTBT on July 26, 1963,
Kennedy called for participation in the treaty and deliberately quoted a Chinese proverb, "A journeyof a thousand miles must begin with a single step," which he quoted even when he first met Nikita
Khrushchev in Vienna in June 1961.46
For Japan, the international agreement on nuclear test ban was what they had really desired andtherefore the U.S. government had an optimistic view on Japan's participation in PTBT. In his reporton East Asian countries' probable reactions to PTBT on July 25, 1963, Joseph A. Yager, Director of the
Office of East Asian Affairs, wrote that "the overwhelming reaction in Japan will be one of relief andencouragement" and "such feelings will be particularly intense in Japan because of the country's having
suffered atomic devastation and being directly in the path of soviet test fallout."47 The United Statesconsidered that Japan's participation in PTBT was almost guaranteed to effectively bring pressure on
ChiCom's nuclear program. When Kennedy called for participation, it was only to three governments,
West Germany, France and Japan, that he sent special invitation letters.48
However, Japan's reaction to PTBT was much more cautious than the U.S. had expected. While
the Japanese government celebrated the success of the Moscow negotiation on July 26, there was no
official comment on whether Japan participated in PTBT at first. 49 The possible reason for theJapanese government's hesitation might be because they had generally considered atmospheric test ban
Masaki Sakamoto, "Kennedy's Nonproliferation Policy and Test-ban Negotiation, 1961-63: The
Formulation of the U.S. Policy toward PTBT," Journal of Laws and Political Science 112 (Spring 2017):
pp. 169-200. (Japanese)
46
Memcon, June 4, 1961, FRUS, 1961-63, Vol. V, doc. 87. "Radio and Television Address to the American
People on the Nuclear Test Ban Treaty," July 26, 1963, PPPUS: John F. Kennedy, 1963 (Washington D.C.,
USGPO, 1964), pp. 601-6. The drafts of the speech show that Kennedy's speech writer Ted Sorensen
considered to use Greek mathematician Archimedes' famous quote, "give me a lever and a place to standand I will move the world," but finally replaced it with the Chinese proverb. Memorandum for Sorensen,
July 25, 1963, NSF, Department and Agencies, Box 264, JFKL.
47
Memorandum: "Public Treatment of Partial Nuclear Test Ban: The East Asian Implications," July 25, 1963,
US Declassified Documents Online (USDDO).
48
July 27, 1963, Yomiuri Shimbun.
49
July 26, 1963, Yomiuri Shimbun.
1545

as the issue facing nuclear weapons states. Therefore, Japanese officials expected the treaty to beconcluded by those having nuclear weapons. When they accepted the invitation of PTBT from theUnited States, it was, if not complete, a kind of surprise and they needed at least some time forconsideration.50 From July 26 to August 9, the Ikeda administration held cabinet meetings several
times while collecting more information on PTBT and the international situation surrounding the treaty
from the embassies and their allied countries.
Yet, it was not only their lack of preparation but also many other "real" issues that led to theirhesitation. First, the Ikeda administration worried that the success of PTBT might bring too much of aeuphoric mood in Japanese society.51 In fact, Foreign Minister Masahiro Ohira, who expressed themost cautious reaction to PTBT among the cabinet members, said in the cabinet meeting on July 26that "we should not have too optimistic a view without reserve."52 There were complicated feelings in
the Ikeda administration toward détente. While Ikeda and his staffs welcomed international agreements
on nuclear disarmament and arms control, they simultaneously feared that the peaceful mood based on
the U.S.-Soviet détente led Japanese people to become more anti-military and anti-nuclear andSocialist party gained more momentum in the Diet.
In addition, the Ikeda administration was also concerned about the extent to which PTBT would
restrain Japan's future actions. While Ikeda had already declared that he had no intention to build up
nuclear defense capability, it was another issue for him to eternally give up the choice of "nucleararmed Japan."53 He realized that the international situation concerning nuclear weapons was still very

50

Actually, even after they accepted an invitation to PTBT, there was an opinion that test ban was the
responsibility of nuclear states and it was useless for Japan to sign the treaty."Bubun Kakutei Joyaku ni
Taisuru Wagakuni no Taido," July 30, 1963, Bubunteki Kakujikken Kinshi Joyaku / Nihon no Sanka Mondai,SB'141, DAJ.
Such concern of Japanese officials about world's euphoria was shared by British officials. "Meeting
between Hogen and Cortazzi," August 9, 1963, Bubunteki Kakujikken Kinshi Joyaku / Nihon no Sanka
Mondai, SB'141, DAJ.
52
July 26, 1963, Yomiuri Shimbun.
53
In the Lower House Budget Committee, Ikeda said that the Constitution itself does not ban nuclear
armament unless it goes beyond the range of self-defense capability, while he made sure that he had nointention to acquire nuclear weapons. March 5, 1961, Asahi Shimbun.
51

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unstable and likely to change. On this point, a report prepared by Kokusai Shiryo Bu (International
Document Section), Ministry of Foreign Affairs, on July 29 said that "PTBT intends to ban any nuclear
tests except those conducted underground and it does not involve the issues of nuclear demilitarizationor nuclear demilitarized zones. Therefore, even if our country joins the treaty, it does not bind our
position on the issues of nuclear demilitarization nor nuclear demilitarized zones in the future."54 In
addition, Kokusai Rengo Kyoku (United Nations Bureau) report on July 30 made it clear again that
PTBT had nothing to do with manufacturing, using and storing of nuclear weapons. It also mentioned
to the fact that the withdrawal clause of PTBT allowed a party to denounce the treaty "if it decides thatextraordinary events related to the subject matter of this Treaty have jeopardized its supremeinterests."55 These reports partly showed how seriously the Ikeda administration considered this point.
Although there were some concerns in the Ikeda administration to accept PTBT, the drive to urge
participation was much stronger. The single and most important factor was that if Japan would not join
the treaty, it would seriously damage the image the Japanese government had been building throughits long effort on nuclear disarmament and arms control negotiation in the United Nations. Particularly,
in his telegram from Geneva to Tokyo on July 29, Ambassador Morio Aoki pointed out thatparticipation in PTBT was important to put pressure on ChiCom's nuclear weapons development and"if ChiCom would not stop, our country could withdraw from the treaty as necessary." He also argued
that if Japan took too long time to decide to sign PTBT, it would invite unnecessary misunderstandingthat Japan might have an ambition to become "the second France." For Aoki, the question was notwhether to join the treaty but when to sign it.56
Ikeda also realized that there was not much time for decision making. In addition to Kennedy's

54"Beieiso Sangoku Bubun Kakutei Joyaku ni Tsuite," July 29, 1963, Bubunteki Kakujikken Kinshi Joyaku /Nihon no Sanka Mondai, SB'141, DAJ.

55

"Bubun Kakutei Joyaku ni Taisuru Wagakuni no Taido," July 30, 1963, Bubunteki Kakujikken Kinshi Joyaku/ Nihon no Sanka Mondai, SB'141, DAJ.

56

Telegram from Geneva to Tokyo, July 29, 1963, Bubunteki Kakujikken Kinshi Joyaku / Kari Choin, 20145396 (admin.), DAJ.
17

special letter, which called for Japan's participation in PTBT, the U.S. government on July 30 madeJohn K. Emmerson in U.S. embassy deliver a talking paper to Shinsaku Hogen and again asked Japanto join the treaty as early as possible. 57 Ikeda understood the need for early decision making anddecided to hold a cabinet meeting on July 31 to reach a conclusion. Unfortunately, the details of themeeting were not declassified, but on the same day, Ohira announced that the Japanese government
had decided to start the process for participating in PTBT.58

6.

Conclusion

When discussing Prime Minister Hayato Ikeda, many studies have argued that he was an "honor
student of the Yoshida Doctrine." The implications of this label they put on him are two-fold. First, as
the Yoshida Doctrine explains, Ikeda's policy generally focused on economic issues while letting
national security largely depend on the U.S.-Japan Security Treaty. Second, the phrase "honor student"means his policy was a copy of that of the former Prime Minister and his mentor, Shigeru Yoshida.
The idea is that he just followed what his predecessor did and kept the course of established policy.
Such an image was also applied to the study of Ikeda's nuclear policy; he never tried to do new things
in nuclear disarmament policy, not to mention "nuclear-armed Japan."This paper does not aim to completely reject these arguments. However, considering the situation
surrounding the Ikeda administration, both domestic and international, a somewhat different image of57

Memcon of Hogen and Emerson, July 30, 1963; Talking Paper Submitted by Emerson, undated, Bubunteki
Kakujikken Kinshi Joyaku / Nihon no Sanka Mondai, SB'141, DAJ.

58

"Bubunteki Kakujikken Kinshi Joyaku ni tsuite no Gaimu Daijin Dan," July 31, 1963, Bubunteki Kakujikken
Kinshi Joyaku / Nihon no Sanka Mondai, SB'141, DAJ. The Japanese government kept studying the effect of
PTBT and observing other countries' behaviors even after the announcement of July 31 until the official
cabinet decision was made on August 8, but it was generallyfocused on the treaty signing process and othermiscellaneous issues. "Waga Kuni no Bubunteki Kakutei Joyaku Sanka ni Tsuite," August 2, 1963,
Kakujikken Kinshi Joyaku / Nihon no Sanka Mondai, SB'141, DAJ.
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him and his nuclear policy can be drawn. When Ikeda assumed office, Japanese domestic politics wasin an extraordinary degree of confusion because of Anpo Toso. In fact, when Ikeda decided to run for
the President of Liberal Democratic Party, Ohira was strongly opposed to it, warning that the prevailingsituation was too extraordinary and too hard to deal with.59 Anpo Toso also cast doubt on the U.S.Japan relationship and required the next Prime Minister to reassure its counterpart. Looking at theinternational situation, the danger of nuclear proliferation had gradually increased while the tension
between the superpowers also began mounting. Such a fluid situation inside and outside Japan forced
Ikeda to deliberately deal with nuclear policy, the most sensitive issue for Japanese society.
As most of the existing studies argue, Ikeda's nuclear policy merely invoked following thefootsteps of his predecessors. He continued to energetically proceed nuclear disarmament and arms
control diplomacy. He reassured the United States on Japan being ready offer the military bases andreaffirmed the agreement on the introduction of nuclear equipment. Those measures did not bring any
great change in Japan's nuclear policy. Yet, if situation is changed, making the same choice may besometimes even more important than it looks. Taking into account the fluid situation inside and outside
Japan as discussed above, Ikeda's nuclear policy was more of "reselecting" rather than just "following
the footsteps."
After undergoing surgery for laryngeal cancer, Ikeda died of postoperative pneumonia on August
13, 1965. When he announced his resignation on October 25, 1964, he designated Eisaku Sato as thenext Prime Minister. On December 11, 1967, Sato declared the Three Non-Nuclear Principles, which
consists of non-production, non-possession, and non-introduction of nuclear weapons. Later, hebroadened it into the Four Pillars Nuclear Policy of (1) promoting the use of atomic energy for peacefulpurposes, (2) commitment to global nuclear disarmament, (3) reliance on the U.S. nuclear deterrent
system, and (4) the Three Principles. These policies provided the basis for Japan's nuclear policy, which
remain the same even today. Thus, it may be natural that the nuclear policy of the late 1960s has drawn

59

Fujii, Ikeda Hayato, p. 227.
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more attention. Yet, it should be noted that these policies were based on the great effort made by Ikeda
during the quiet crisis after the turbulence of Anpo Toso. In this sense, the early 1960s is, if not more,
as important as the late 1960s for Japan's post-war nuclear policy and for the U.S.-Japan nuclear
relationship.

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