The year 2000 marks the 40th anniversary of the signing of the current Japan-U.S. Security Treaty. During those 40 years, the bilateral alliance has played a significant role in the security of Japan and the region.

　On the other hand, aspects of the alliance remain shrouded in secrecy, and this lack of transparency could potentially undermine the equality of the two partners in the alliance.

　The 1996 Japan-U.S. joint declaration on security mandated the strengthening of the alliance into the 21st century and the maintenance of some 100,000 forward-deployed U.S. troops, and affirmed that the treaty would cover areas surrounding Japan.

　Ever since the treaty was concluded, however, it has in reality always had a hidden side concerning emergencies on the Korean Peninsula. Furthermore, while Japan has maintained the three principles of not making, possessing or bringing into its territory nuclear weapons, there has long been a double standard concerning the third principle. Both of these discrepancies are due to secret agreements between the two governments.

　Articles 5 and 6 of the security treaty form a pair. In the event Japan is attacked by force, the United States will act jointly with Japan to deal with the situation. In return, Japan provides military bases to the United States for the maintenance of peace in the Far East.

　One must remember the circumstances of the two countries four decades ago, when they concluded the treaty: Japan desperately wanted to regain its footing as an independent state and overcome the subordinate status it was forced to accept after being occupied by Allied forces. The United States, on the other hand, was intent on protecting the rights it had acquired during the occupation. Thus the two sides seemed to be fiercely at odds over the signing of the treaty.

　As a result of negotiations, the two countries agreed to hold consultations prior to any one of three eventualities: major changes in the deployment into Japan of U.S. armed forces, major changes in their equipment, and the use of facilities and areas as bases for military combat operations.

　However, documents show that agreements were reached behind the scenes on Jan. 6, 1960, just before the conclusion of the treaty, between then Foreign Minister Aiichiro Fujiyama and U.S. Ambassador to Japan Douglas MacArthur II.

　The first of these documents is "The Minutes of a Preparatory Meeting of the Japan-U.S. Security Consultative Committee,'' in which the two sides secretly agreed to forgo prior consultations in the event U.N. forces in the Republic of Korea (South Korea) were attacked and U.S. forces stationed in Japan took part in combat operations under the unified command of U.N. forces. In other words, they agreed that U.S. troops stationed in Japan could freely go into action from bases in Japan to deal with an emergency on the Korean Peninsula.

　The second document is the "Record of Discussion'' between Japanese and U.S. negotiators concerning which circumstances require prior consultations and which do not. Two of the four points that the two sides agreed on concerned the introduction of nuclear weapons as follows: 1) "Major changes in their equipment'' is understood to mean the introduction into Japan of nuclear weapons, including intermediate and long-range missiles as well as the construction of bases for such weapons, and will not, for example, mean the introduction of non-nuclear weapons including short-range missiles without nuclear components; 2) "Prior consultation'' will not be interpreted as affecting present procedures regarding the deployment of U.S. armed forces and their equipment into Japan and those for the entry of U.S. military aircraft and the entry into Japanese waters and ports by U.S. naval vessels, except in the case of major changes in the deployment into Japan of U.S. armed forces.

　Tokyo has always maintained that one of its three non-nuclear principles−not bringing nuclear weapons into Japan−also applies to the passage and arrival at Japanese territorial waters, airspace and ports of aircraft and warships carrying nuclear weapons. But it appears the government was only paying lip service to this ideal.

　Actually, the U.S. side distinguished "introduction,'' which means installing and storing nuclear weapons on Japanese soil, from "transit'' and "entry,'' which mean passage and port calls. The latter had practically become routine.

　A telegram that U.S. Ambassador to Japan Edwin Reischauer sent to the State Department has also come to light. Reischauer met Foreign Minister Masayoshi Ohira at the ambassador's residence on the morning of April 4, 1963, and showed him the Record of Discussion concerning prior consultations. Reischauer pointed out that the government's explanation of the matter in the Diet differed from the understanding reached between Japan and the United States at the time of the treaty negotiations.

　According to Reischauer's telegram, Ohira replied: "While Japanese had not in past used mochikomu with consciousness of this restricted sense, they would so use it in future. According to the Japanese government's official explanation, the Japanese word mochikomu can mean all of the following: introduction to Japanese soil, entry to ports and passage through territorial waters and airspace.

　Free use of Japanese bases to deal with emergencies on the Korean Peninsula and bringing in nuclear weapons are both secret arrangements that could expose the Japanese people to danger should an emergency occur.

　Masaaki Gabe, a University of the Ryukyus professor who is trying to uncover the truth by carefully studying declassified U.S. official documents, said, "Without the Japanese people's support, based on transparent relations in accordance with a treaty, true crisis management cannot be carried out.''