08/06/2012 09:14 pm ET Updated Oct 06, 2012

Japan's Reassuring Nuclear History

As we commemorate the 67th anniversary of the bombings of Hiroshima and Nagasaki, the people of Japan are engaged in a national debate over the future of nuclear energy in their country, a debate brought on by last year's catastrophic nuclear accident at Fukushima. The intrinsic connection between nuclear energy and nuclear weapons are a key part of the discussion.

The Fukushima disaster intensified an investigation of Japan's nuclear history that was already well underway. After its electoral victory in 2009, the Democratic Party of Japan (DPJ) initiated a review of Japanese foreign and defense policy that exposed a long record of Japanese government complicity with U.S. nuclear weapons policies that violate Japanese laws forbidding U.S. nuclear weapons on Japanese territory. It also uncovered documents that indicate Japan had seriously considered acquiring its own nuclear weapons.

U.S. concerns about Japan's interest in nuclear weapons are nothing new, and were cited as a reason to redeploy U.S. tactical nuclear weapons in Asia in a 2009 report on U.S. nuclear policy by a congressional commission headed by two former defense secretaries, William Perry and James Schlesinger. Many U.S. defense analysts and policymakers believe the only thing preventing Japan from acquiring nuclear weapons is the U.S. security guarantee, which features a "nuclear umbrella" supported by U.S. nuclear forces. Their perspective is reinforced by occasional comments from a handful of Japanese conservatives, such as former Defense Minister Shigeru Ishiba, who suggested Japan needed to maintain its nuclear energy program to leave open the option of developing nuclear weapons.

Ishiba's comments were featured in recent Associated Press story on the connection between Japanese protests against nuclear energy and the bomb. "Historical documents released in the past two years show that the idea of a nuclear-armed Japan was long talked about behind-the-scenes," the AP reported, "despite repeated denials by the government."

The AP reporter assumed these secret Japanese talks argued in favor of developing nuclear weapons, or at least, as Ishiba suggested, maintaining the option. But the documents that describe the secret Japanese government deliberations about nuclear weapons, which occurred in the context of country's consideration of the Nuclear Non-Proliferation Treaty (NPT), actually tell a different and more reassuring story.

In 1995, the Japanese Foreign Ministry was negotiating the permanent extension of the NPT. At the same time, the Japan Defense Agency (JDA) conducted a study on the proliferation of weapons of mass destruction. The 1995 JDA report, which was not released publicly, carefully considered the question of whether Japan should develop its own nuclear arsenal as well as the circumstances that might trigger such a decision. The worst-case scenario envisioned a complete collapse of the NPT and the break-up of the U.S.-Japan security alliance. The report concluded: "Even in such a case, it is questionable whether there is any value for a trading nation that depends on the stability of the international society to try to secure its survival and protect its interests with its own nuclear weapons. It would more likely undermine the basis of its own survival."

The report, conducted by some of Japan's most conservative defense analysts, went on to state that neither a nuclear North Korea nor a large-scale war between the United States and China would alter its view that "the nuclear option is not a favorable one for Japan."

The 1995 JDA report reflected a longstanding consensus among Japanese security officials and experts that there is no imaginable scenario in which developing nuclear weapons would be advantageous to the defense of Japan. It reiterated and amplified the conclusions of an earlier report on Japan's nuclear options -- also hidden from the public -- commissioned by the Japanese government in 1968 when it was initially considering ratifying the NPT.

The two reports on Japan's nuclear options were kept secret because the Japanese governments that commissioned them were afraid that even considering a nuclear option would incite massive public protests. Japanese public opinion polls consistently register high levels of support for nuclear disarmament and strong opposition to Japanese development of nuclear weapons.

Increased Japanese transparency about its nuclear history and the public discussion it has triggered should not be a cause for alarm. They are welcome developments that are likely to solidify Japan's long-standing and well-considered opposition to developing nuclear weapons. U.S. policymakers should stop calibrating U.S. decisions about Japan's national security interests according to the speculations of outliers like Mr. Ishida and respect the desires of the overwhelming majority of Japanese citizens who support nuclear disarmament.