1. The Japanese Government's Nuclear Policy and the Three Non-Nuclear Principles
The centerpiece of the Japanese government's security policy is the policy of dependent on expanded US deterrent strength. At the same time, against the backdrop of the strong anti-nuclear sentiment among the Japanese people, the foundation of nuclear policy has been the three non-nuclear principles (nonpossession, nonproduction, and nonintroduction). But as the nuclear depending policy and these three principles involve contradictions, they have for many years been the object of controversy in Japan.
Dependence on expanded US deterrent strength, which is at the foundation of Japan's national security policy, made its first appearance in an official document in the 1976 National Defense Program Outline (NDPO), which read, "Japan depends on US deterrence against nuclear threats."
The three non-nuclear principles were shaped in the process of Japan-US talks over the return of administrative authority of Okinawa. On the occasion when the US returned to Japan this authority over Okinawa, where the US had deployed many nuclear weapons, in December 1967 Prime Minister Eisaku Sato made the first government statement, in response to questions in the Diet, as a guarantee that Okinawa would be returned free of nuclear weapons. In subsequent Diet hearings on the Okinawa return agreement, the House of Representatives plenary session adopted a resolution which included the three non-nuclear principles, and they became basic national policy with the statement by Prime Minister Sato that the government would comply with them.
It is important to realize that the three non-nuclear principles are not in themselves a stand-alone policy. In a House of Representatives plenary session in January 1968, just after Prime Minister Sato announced the principles, he added three policies to the principles to make the "four nuclear policies." Those three policies were: Make efforts for achievable nuclear disarmament, depend on US nuclear deterrence against international nuclear threats, and work for the peaceful use of nuclear energy. As this shows, one must understand the three non-nuclear principles as part of a set of policies depending on nuclear deterrence.
If the three principles are rigorously implemented and nuclear weapons are not allowed into Japan at all, one must recognize the possibility that US nuclear forces will not function adequately in the Japan region. For example, according to the Japanese government's unified view, the government does not recognize the rights of innocent passage through Japanese territorial waters for US warships carrying nuclear arms, and when a warship carrying nuclear arms is to pass through Japanese territorial waters, it is subject to prior consultation under the Japan-US Security Treaty, and as a rule will not be permitted. Therefore, Japan's nuclear policy and security policy have had a grave contradiction from the outset.

2. History of the Secret Nuclear Agreement
Until the present, the Japanese government's stance has been that if the US is going to bring nuclear weapons into Japan's territorial waters, it would be subject to prior consultations under Article 6 the Japan-US Security Treaty, and that as a rule Japan would not consent. But it is has been revealed that there was a secret Japan-US pact on the introduction of nuclear arms. Japan's stance until now has been to deny the agreement's existence.
The history of the secret agreement on introducing nuclear weapons goes back to negotiations on revising the Security Treaty, which started in October 1958. Under the original treaty, US forces would continue to be stationed in Japan as they were after the war's end, and no restrictions at all were imposed on bringing nuclear arms onto US bases in the main islands or Okinawa. But the campaign to ban nuclear weapons in Japan widened owing to the exposure of a Japanese fishing vessel and its crew in the 1954 Bikini Atoll test, and the free introduction of nuclear arms as practiced under the original treaty could no longer be done openly under the revised treaty.
The Japan-US Security Treaty was signed on January 19, 1960, at which time Prime Minister Nobusuke Kishi and Secretary of State Christian Herter conducted an exchange of notes on the implementation of Article 6, agreeing that the US would consult with the Japanese government in advance regarding important changes in the deployment of US military forces in Japan, important changes in the equipment of those forces, and combat operations and actions conducted from Japan, other than for Japan's defense (Article 5). Additionally, it is said that there was an oral understanding on the application of the prior consultation system that the introduction of nuclear weapons is included in "important changes in equipment." However, on January 6, shortly before the treaty signing, Foreign Minister Aiichiro Fujiyama and US Ambassador to Japan Douglas MacArthur II had already signed a secret record of discussion, which includes a statement that it is not interpreted to mean that the record affects current procedures concerning the entry of US warships and military aircraft into Japan (free introduction of nuclear arms under the original Security Treaty) (Secret Agreement 1).
Subsequently the US pressured the Japanese government so that it would do nothing to violate the secret pact. In 1963 US Ambassador Edwin Reischauer met with Foreign Minister Masayoshi Ohira about the Diet statement by Prime Minister Hayato Ikeda port calls in Japan by US nuclear-powered attack submarines were subject to prior consultation, which Reischauer saw as problematic. They confirmed the substance of the record of discussion, and Foreign Minister Ohira confirmed the secret agreement on nuclear arms introduction. Likewise in 1964, Reischauer found fault with a Diet statement by a high government official on port calls by nuclear-powered submarines, and held another meeting with Ohira (who was then the ruling Liberal Democratic Party's secretary-general), and confirmed the secret agreement.
The second scene concerning nuclear arms introduction was in the Japan-US negotiations on the return of administrative authority over Okinawa. There was a strong campaign by Okinawans for reversion, and owing to concerns that the US military bases in Okinawa, which were used for missions in the Vietnam War, would find themselves unable to function smoothly the US took decided to return administrative authority over Okinawa. Because many nuclear weapons were deployed in Okinawa at that time, their removal became the biggest focus on the occasion of turning over Okinawa to Japan. Returning Okinawa "with nukes" was impossible in the face of strong public opinion demanding the abolition of nuclear weapons. At the same time, however, reversion of administrative authority over Okinawa meant that the Security Treaty and its related agreements (including the secret agreement) would apply to Okinawa.
Item 8 of the joint statement on the reversion of Okinawa by Prime Minister Sato and President Richard Nixon in November 1969 states: "The Prime Minister described in detail the particular sentiment of the Japanese people against nuclear weapons and the policy of the Japanese Government reflecting such sentiment. The President expressed his deep understanding and assured the Prime Minister that, without prejudice to the position of the United States Government with respect to the prior consultation system under the Treaty of Mutual Cooperation and Security, the reversion of Okinawa would be carried out in a manner consistent with the policy of the Japanese Government as described by the Prime Minister." If one recalls Secret Agreement 1, which was exchanged when the Security Treaty was revised, one can understand the meaning of this joint statement. Sato and Nixon further signed secret agreement minutes concerning the joint statement. These agreement minutes said that in the event of an emergency situation, the Japanese government pledges its consent in prior consultations for the US introduction of nuclear weapons into Okinawa (Secret Agreement 2).
These two secret pacts enabled the US to freely bring nuclear weapons into Japan, and to use US bases in Japan as focal points of its nuclear strategy. At the same time, it enabled the Japanese government to offer the Japanese people the explanations that the US also respects the three non-nuclear principles, that there is a prior consultation system under the Security Treaty, and trust is the foundation of the alliance, and that because there has been no request for prior consultations from the US, it follows that nuclear weapons have not been introduced into Japan. But this deceived the Japanese people. And this deception notwithstanding, many Japanese believe that nuclear weapons have been brought into Japan.

3. The Democratic Party Administration and the Secret Nuclear Agreements
As is widely known, under the George H. W. Bush (Bush 41) administration in 1991, the US removed all strategic nuclear weapons deployed abroad, and cancelled the nuclear mission of the Marines, naval aircraft, and warships. Does that mean the secret agreements on nuclear arms introduction are already something of the past? That is in fact being discussed in Japan, but the agreements are still very much alive. Even now the US maintains the nuclear missions of some Air Force units and some nuclear-powered submarines, and submarines so tasked visit Japanese ports. In a contingency, it is certain that nuclear weapons would be deployed to these submarines and Air Force units, and that nuclear weapons would be brought into Japan. The US still upholds its NCND policy.
That the Japanese government knows best that nuclear weapons could be brought into Japan is proved by the following fact. On April 1, 2009 the Congressional Commission on U.S. Strategic Posture (chaired by former Secretary of Defense William J. Perry) submitted a report. It is believed that his report will heavily influence the review of the US nuclear posture being conducted by the Obama administration. In preparing its report, the commission conferred closely with the governments of allies and friendly nations. At the end of the report is a list of the people from each government with whom the commission conferred, and the names of four diplomatic officials at the Japanese Embassy in the US are given first as Japanese government officials. After Japan come other countries including Denmark, Turkey, Germany, France, and Israel. The officials at the Japanese Embassy in the US submitted a three-page memorandum stating the Japanese government's position, apparently telling the commission that Japan opposes the decommissioning of the nuclear cruise missiles deployed on a nuclear-powered submarine scheduled for decommissioning in 2013, and making these requests: low-yield earth penetrating nuclear weapons enhance the reliability of the nuclear umbrella; Japan wants prior consultation on the decommissioning of submarine-launched nuclear Tomahawk missiles; and Japan wants details on nuclear forces and tactical nuclear plans. This shows that not only does the Japanese government consent to bringing nuclear weapons into Japan under the secret agreements, but also desires it, the reason being that maintains the effectiveness of the nuclear deterrence policy, which is the centerpiece of Japan's security policy.
The reality is that the secret agreements on introducing nuclear weapons even now continue to limit Japan's sovereignty. As having territorial waters of 12 nautical miles was already taken for granted internationally during negotiations for the United Nations Convention on the Law of the Sea (UNCLOS), in 1977 the Japanese government enacted the Territorial Waters Act and set Japan's territorial waters to 12 nautical miles. At the same time it set territorial waters to three nautical miles in the straits of Soya (La P?rouse), Tsugaru, and Tsushima. Even though both sides of these straits are Japanese territory, the territorial water limits were set at three nautical miles, which made parts of the straits into international waters, and is highly unusual from an international point of view. Why was this done?
Before these lines were drawn, the US was concerned that if the 12 nautical miles from shore were another country's territory under UNCLOS, it would limit the free movement of nuclear submarines and impose a serious impediment on the performance of plans for nuclear war in accordance with the Single Integrated Operational Plan (SIOP). This was because although submarines have the right if innocent passage in other countries' territorial waters, they must do so by surfacing and hoisting their national flags, which would make it impossible for nuclear submarines to carry out their tactical nuclear missions. The US lobbied the Japanese government intensively. To Japan's government there was also the concern that if strategic and attack nuclear submarines were to pass through these straits while surfaced, it would create a serious political problem because the submarines would be seen as openly bringing nuclear weapons into Japan. Hence the choice made by the Japanese government, which was bound by the secret agreements on introducing nuclear weapons, was to give those straits exceptional treatment. Even now, the waters in these straits beyond three nautical miles from shore are international.
Japan's government changed and is now administered by the Democratic Party of Japan (DPJ). Foreign Minister Katsuya Okada sent a letter to US Secretary of State Hillary Clinton and stated that Japan does not oppose the decommissioning of nuclear-armed Tomahawk cruise missiles. On March 9 the DPJ administration released the results of its investigation of the secret agreements. Foreign Minister Okada then expressed the view that the secret agreements are an issue of the past because, owing to the 1991 Bush initiative, it is no longer possible to conceive of a situation in which nuclear weapons are brought into Japan. Prime Minister Yukio Hatoyama stated that the three non-nuclear principles would continue to be observed. However, it is quite possible that nuclear weapons would be introduced in the event of armed conflict in the Japan region. As introduction of nuclear weapons is still possible, if the government's stance is to observe the three non-nuclear principles, the government must properly provide for consistency with US policy for introducing nuclear weapons in a contingency. The DPJ claims that the secret agreements are a problem of the past, and that the introduction of nuclear weapons from now on is impossible, thereby doing nothing about the contradiction between US nuclear policy and the three non-nuclear principles. This DPJ posture could create the departure point for a new secret pact.
Japan's future security policy is being called squarely into question.

4. Scrap the Secret Agreements, and Enact a Non-Nuclear Law that Includes the Three Non-Nuclear Principles
Japan's government has launched talks with the US aiming to deepen the Japan-US alliance, with an eye to the next 50 years of the Japan-US security regime, and there are plants to issue a joint security declaration at the Japan-US summit meeting with President Obama, who is scheduled to visit Japan this autumn. The main topic of discussion will be making expanded deterrence function effectively.
Paragraph 105 (2) F of the International Court of Justice Advisory Opinion says of non-nuclear weapon states, "There exists an obligation to… bring to a conclusion negotiations leading to nuclear disarmament." All countries that participated in the 2000 NPT RevCon, including Japan, agreed to its Final Document, which, in connection with the performance of NPT Article VI, agrees on 13 steps for nuclear disarmament including diminishing the role of nuclear weapons in security policy, enhanced regimes for nuclear non-proliferation by nuclear-free zones, and making a contribution to nuclear disarmament. According to Article 31.3. of the Vienna Convention on the Law of Treaties, the Final Document can be understood as the content of the NPT's Article 6. In this light, the Japanese government is obligated under international law to implement Sub-paragraph F of the ICJ Advisory Opinion, change its policy of dependence on expanded deterrence, and take measures for nuclear disarmament, including the realization of the Northeast Asia Nuclear-Free Zone.
Additionally, the Security Council summit of September 24, 2009 adopted resolution 1887, which states that nuclear weapon-free zones strengthen the nuclear non-proliferation regime. The government of Japan agreed in its capacity as a UNSC member. In view of its capacity, Japan's government has the political responsibility to make the Northeast Asia Nuclear-Free Zone a reality.
If the Japanese government reconsiders its policy of dependence on US expanded deterrence, chooses a security policy that does not depend on nuclear deterrence, and instead takes a stand for realization of the Northeast Asia Nuclear-Free Zone, it would also facilitate the Obama administration's nuclear disarmament initiative. It could also play the role of furthering the six-party talks that discuss the issue of North Korea's nuclear weapons development.
We Japanese lawyers ask the Japanese government to abandon its policy of depending on nuclear deterrence, and to adopt an initiative for bringing about the Northeast Asia Nuclear-Free Zone, which would be an alternative security policy that does not depend on nuclear weapons.
We ask the Japanese government to enact what might be called a "Non-Nuclear Law" that would include the three non-nuclear principles. One must be aware that countries near Japan always see a threat in Japan's large store of plutonium, the government's constitutional interpretation that Japan may possess nuclear weapons if they are purely for defensive, the argument for having nuclear weapons that emerges on just about any occasion, Japan's possession of technologies for satellite launching and making nuclear weapons, arguments for revising Article 9 of the Constitution, and more. Japan needs a domestic law that will never allow such backsliding. It would also be seen as a domestic law for implementation of the Northeast Asia Nuclear-Free Zone Treaty to be signed in the future.