Nuclear Power and Japan's National Security

Tetsuo Arima
Professor, Faculty of Social Sciences, Waseda University

On May 7, 1957, one and a half months before making a visit to the U.S., Prime Minister Nobusuke Kishi presented his theory on the constitutionality of nuclear arms as a means of self-defense before the House of Councilors Cabinet Committee, as follows:

Nobusuke Kishi: The various weapons that are used under the term "nuclear weapons". are considered unconstitutional simply by virtue of the fact that they are called "nuclear weapons". However, that is not necessarily the case. The spirit of our Constitution is, ultimately, self-defense, and so it stands to reason that equipping ourselves with one of the powers included under the right of self-defense is permissible under our current interpretation of the Constitution. (From the website "Search System of the Minutes of the Proceedings of the National Diet" [Kokkai Kaigiroku Kensaku Shisutemu])

Why did Kishi make such an assertion at this point in time? It was because the purpose of his visit to the U.S. was to pave the way for the revision of the Japan-U.S. Security Treaty (hereafter referred to as "Security Treaty").

The Security Treaty, which had been signed at the same time as the San Francisco Peace Treaty, was just as disadvantageous for Japan as the unequal treaties at the end of the Tokugawa era. Japan had been forced to accept demands to put an end to the Allied occupation.

Despite the fact that U.S. forces were not under any obligation to defend Japan, the treaty allowed them to station troops anywhere they liked and did not place any restrictions on them, even with regard to bringing nuclear weapons into the country. In addition, the treaty had no expiration date and could not be annulled by the Japanese side.

Kishi wanted to revise the treaty to make it more equitable. Under the revision, Japan would provide the U.S. with a number of military bases, while the U.S. would withdraw most of its ground forces from Japan. The U.S. would not be allowed to bring in nuclear weapons that could entangle Japan in a nuclear war. The treaty would be set to expire ten years after the date of the revision, and the two countries would be able to renegotiate and renew the treaty every ten years.

The problem with Kishi's proposed revision was that a considerable portion of the U.S. ground troops would be withdrawn, leaving Japan almost entirely defenseless and vulnerable to threats from China and the Soviet Union. These two countries had formed an alliance in 1950, and the Soviet Union posed a special threat due to its possession of nuclear weapons.

Kishi thus asserted that nuclear armament was permissible for the purpose of self-defense, even under the existing Constitution. Indeed, the revision Kishi had planned would not have been feasible had he not made this assertion.

The U.S. was deeply shocked by Kishi's speech on the constitutionality of nuclear arms. In fact, the CIA launched a full-scale investigation of Japan's nuclear-arms capability after Kishi returned to Japan. The following quote summarizes the findings of a CIA intelligence report dated July 26, 1957:

One capable U.S. government official believes that if Japan succeeds in using the uranium recent reports say it has been storing as fuel for a nuclear reactor, it will be able to produce nuclear weapons by 1967 without the assistance of other countries. The Japanese are making every effort to remove any impediment (meaning report of Japan's uranium stockpile, author's notes are parenthesized hereinafter) standing in their way. The Japanese government has been rapidly advancing domestic and international programs in order to secure a sufficient amount of uranium to pursue a major nuclear power program free of the restrictions imposed by the U.S. and the U.K. on their use of nuclear byproducts (such as plutonium) related to the export of nuclear fuel from those countries.
If the Japanese receive an unlimited supply of nuclear fuel and successfully produce their own nuclear power plants, they will obtain nuclear material (plutonium) that can be used for nuclear weapons. If the nuclear reactor they use is a British Calder Hall type reactor or a reactor that uses natural uranium, it will provide them with a massive supply of nuclear material. (From a U.S. State Department document in the U.S. National Archives II)

Matsutaro Shoriki, then Chairman of the Atomic Energy Commission (as well as Chairman of the National Public Safety Commission) under the Kishi administration, had been pushing forward plans to install a Calder Hall nuclear power plant from Britain, despite the opposition of the U.S. government. Thus, Kishi's theory on nuclear arms for self-defense was not just a castle in the air.

The U.S. government was forced to make a choice between accepting the revision of the Security Treaty or allowing Japan to develop nuclear arms. They chose the former option. After the passage of several other events, the Security Treaty was revised in 1960.

Japan's first nuclear power plant, the Tokai Power Station, began operation in 1966. Once the plant was producing about 50 kilograms of plutonium per year, the U.S. put pressure on Japan to join the Nuclear Non-Proliferation Treaty (NPT) in order to limit Japan's nuclear-arms capability. The Japanese Prime Minister at that time, Eisaku Sato, ordered researchers to examine whether Japan should join the treaty or continue developing its nuclear arms. (Sources documenting this history include a classified document of the Cabinet Intelligence and Research Office, Basic Research on Japan's Nuclear Policy [Nihon no Kakuseisaku ni kansuru Kisoteki Kenkyu])

As a result, Japan decided to stop developing nuclear arms for the time being and continue receiving nuclear fuel from the U.S., working to meet the country's burgeoning electricity demands and achieve economic prosperity through the generation of nuclear power. Japan signed the NPT in 1970, although the ratification of the treaty in the National Diet dragged on for years afterward to the irritation of the U.S. government. Japan officially joined the treaty in 1974, after it had regained possession of Okinawa and renewed diplomatic relations with China.

Japan's national security is thus intimately bound up with nuclear power. Nuclear power generation has provided Japan with more than just electricity. In a post-3.11 Japan, we need to identify the ways in which these two factors are interconnected and think about how we can improve the relationship between them.

Tetsuo Arima
Professor, Faculty of Social Sciences, Waseda University

Professor Arima specializes in television studies and media history. His major publications include Nippon Television and the CIA: The Discovery of the "Shoriki File" [Nippon Terebi to CIA: Hakkutsu Sareta "Shoriki Fairu"] (Shinchosha Publishing), Nuclear Power, Shoriki and the CIA: The Underground History of the Showa Era Revealed by Classified Documents [Genpatsu / Shoriki / CIA: Kimitsu Bunsho de Yomu Showa Rimenshi] (Shincho Shinsho), Nuclear Power and Nuclear Bombs: The Secret Struggle among Japan, the U.S. and Britain over Nuclear Arms [Genpatsu to Genbaku: "Nichi / Bei / Ei" Kakubuso no Anto] (Bunshun Shinsho)