Politics of Well-Known Japanese “Secrets” Risk American Nuclear Umbrella

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Politics of Well-Known Japanese “Secrets” Risk American Nuclear Umbrella

March 24, 2010 5 min read Download Report
Bruce Klingner
Senior Research Fellow, Northeast Asia
Bruce Klingner specializes in Korean and Japanese affairs as the Senior Research Fellow for Northeast Asia.

On March 9, a Japanese foreign ministry panel revealed that several military agreements between Tokyo and Washington had been kept secret from the Japanese legislature and public for decades. The panel was created ostensibly to fulfill a Democratic Party of Japan (DPJ) campaign pledge to improve government transparency. But the report conveniently provides the DPJ a political opportunity to lambast the Liberal Democratic Party’s (LDP) “lies” and “dishonesty” in the run-up to July’s legislative elections. The DPJ, pummeled by bribery scandals and faulty leadership, is already facing plummeting public support.

Although the DPJ insists that this report will not affect its relationship with Washington, the already tense bilateral U.S.–Japan partnership could very well be further strained. These revelations could inflame anti-U.S. opinion, particularly on Okinawa, as the DPJ struggles to produce alternatives to an existing agreement on the realignment of U.S. military forces in Japan. The task force results could also prompt the DPJ to advocate policies during the April nuclear summit in Washington that would undermine U.S. nuclear deterrence capabilities.

Task Force Assesses “Secret” Agreements

Japanese Foreign Minister Katsuya Okada commissioned the investigative task force shortly after the Democratic Party of Japan assumed power September. The panel was tasked to look into four secret agreements between the U.S. and Japan.[1]

The so-called “secret agreements” have been publicly well-known for decades. Former U.S. Ambassador to Japan Edwin Reischaeuer confirmed in a 1981 interview with Mainichi Shimbun that U.S. naval vessels carrying nuclear weapons routinely visited ports in Japan with the tacit approval of the Japanese government.[2] There have been media references to the agreements since at least 1971, and U.S. government documents on the issue were released during the 1990s.[3]

Potential Repercussions for U.S.–Japan Relationship

Okada declared that the task force results would have no impact on U.S.–Japanese relations since the only objective was to restore public trust by exposing the LDP’s past perfidy. However, Japanese opponents of the planned construction of a U.S. air base in Okinawa may capitalize on the report to incite anti-U.S. sentiment. Activists, including members of the DPJ coalition, could point to the agreements as justification for further reducing the U.S. forward-deployed presence on Okinawa. The task force results would also affirm DPJ perceptions of the need to demand a more equal alliance with Washington.

Moreover, by exposing the contradictory and hypocritical nature of Japan’s nuclear posture, the task force report may raise questions over the nature of Washington’s extended deterrence guarantee (“nuclear umbrella”) for the defense of Japan and South Korea. For decades Tokyo has embraced three non-nuclear principles that prohibit the manufacture, possession, or introduction of nuclear weapons into Japan. Tokyo has also depicted itself as a uniquely qualified advocate for a nuclear-free world, since it is the only nation to have suffered the effects of atomic weapons.

At the same time, however, Japan has long relied on U.S. nuclear weapons as a key underpinning of its security. Successive Japanese leaders, including the present administration, have denied any inherent contradiction in these positions.

Tokyo Claims No Contradiction in Nuclear Policy

In explaining Japan’s long-standing aversion to revealing the nuclear agreements, the task force commented that Japanese officials at the time were concerned that forcing the U.S. to scrupulously engage in prior consultations for naval port calls risked preventing all U.S. ships from entering the country—thus endangering the Japan–U.S. Security Treaty and Japan’s security.[4] Washington formally suspended its ANZUS (Australia, New Zealand, United States) Security Treaty obligations to New Zealand as a result of New Zealand denying a U.S. request for a port call by a nuclear-capable destroyer in 1985.

Following publication of the task force report, Prime Minister Yukio Hatoyama asserted that the three non-nuclear principles and U.S. nuclear strategy can coexist, but he did not offer any explanation as to how his administration’s view differs from that of previous LDP governments. Okada affirmed that Tokyo would continue to bar U.S. nuclear weapons from Japanese territory and waters but dismissed the need to either request that Washington alter its “neither confirm nor deny” policy or certify that U.S. vessels are not carrying nuclear weapons. Okada naively claimed “we can determine from the appearance” whether a ship is carrying tactical nuclear weapons and can “identify by the model of ship or aircraft whether it is carrying strategic nuclear weapons.”[5]

The Socialist Democratic Party of Japan, a DPJ coalition partner, has called for converting the three non-nuclear principles into legislation to make them binding on Japanese policymakers. During last year’s legislative election campaign, Hatoyama suggested to a group of atomic bomb survivors in Nagasaki that the principles should be written into law. Last year, Okada advocated that Japan call upon nuclear countries, particularly the U.S., to issue no-first-use pledges, that there be an agreement that use of nuclear weapons against non-nuclear countries is illegal, and that northeast Asia adhere to the concept of being a non-nuclear region.


In response to the uproar over these “revelations” the U.S. should:

  • Reject Japanese calls to adopt a no-first-use nuclear strategy or declare a nuclear-free zone in northeast Asia. Acquiescing to DPJ requests would undermine U.S. deterrent and defense capabilities for its Asian allies and risk increasing—rather than decreasing—the potential for conflict.
  • Refuse an invitation for a presidential visit to Hiroshima. Japanese media and experts advocate that President Obama visit Hiroshima, the site of the world’s first use of atomic weapons, to signal his resolve for a global eradication of nuclear weapons. The symbolism of a presidential visit is so loaded that it cannot but be seen as an apology. And an apology is entirely inappropriate given the causes and course of the Second World War, which resulted in the use of atomic weapons. The U.S. and Japan today are strong allies with common values and systems of governance. The alliance does not at all benefit from a resurrection—for the sake of domestic Japanese political consumption—of the debate over the judgments that led to America’s victory in World War II.
  • Conduct a joint security review. Disputes over security issues will continue to plague the bilateral relationship as long as Washington and Tokyo have such diverse security visions. The DPJ, which did not receive intelligence briefings while an opposition party, perceives a more benign threat environment than successive U.S. Administrations. As a first step, the two sides should engage in a comprehensive joint threat assessment to exchange intelligence and military data on Asian security challenges.
  • Define a comprehensive bilateral security strategy. This strategy should address security threats through a prioritized application of military, diplomatic, and economic instruments of national power as well as a division of duties. The U.S. should reject DPJ advocacy for adopting a low-risk foreign policy that minimizes Japanese security responsibilities.

A Bumpy Road Ahead

The DPJ has announced another investigatory panel to examine other LDP foreign and security policy decisions, including the Koizumi administration’s decision to send troops to Iraq in response to U.S. requests.[6] While the DPJ may see merit in continuing to pursue investigations of past government policies as a way of inflicting political damage on the opposition LDP, doing so may have unintended consequences, such as further harming U.S.–Japanese relations.

The DPJ harbors a different security vision from the U.S. that, combined with its amateurish policymaker style and Hatoyama’s difficulty in making decisions, indicates a bumpy road ahead for the bilateral alliance.

Bruce Klingner is Senior Research Fellow for Northeast Asia in the Asian Studies Center at The Heritage Foundation.

[1]The four reported agreements were regarding allowing port calls in Japan of U.S. vessels carrying nuclear weapons, the use of U.S. bases in Japan for a crisis in Korea without prior consultations, the reintroduction of U.S. nuclear weapons into Okinawa during a crisis, and Japanese compensatory payments during the reversion of Okinawa to Tokyo from U.S. control.

[2] Time, “Japan: Time to Confess, Nuclear ‘Lie’ Strains U.S. Ties,” June 8, 1981, at http://www.time.com/time/magazine/article/0,9171,922558,00.html (March 24, 2010).

[3]Hans Kristensen, “Japan Under the U.S. Nuclear Umbrella,” Nautilus Institute, http://www.nautilus.org/archives/library/security/papers/Nuclear-Umbrella-1.html (March 24, 2010).

[4]Toshimitsu Miyai and Chikara Shima, “Secret Deals Put Government on Horns of Dilemma,” Yomiuri Shimbun, March 11, 2010, at http://www.yomiuri.co.jp/dy/national/20100311TDY03102.htm (March 24, 2010).

[5] Asahi Shimbun, “Okada: Nuclear Weapons Ban Unchanged,” March 11, 2010, at http://www.asahi.com/english/TKY201003100444.html (March 24, 2010).

[6]William Brooks and Mindy Kotler, “DPJ Sees Weapons of Mass Persuasion in LDP Support of Iraq,” Asia Policy Point, March 14, 2010, at http://newasiapolicypoint.blogspot.com/2010/03/dpj-sees-weapon-of-mass-persuasion-in.html (March 24, 2010).


Bruce Klingner
Bruce Klingner

Senior Research Fellow, Northeast Asia