TOKYO — A SOLITARY crime is gradually provoking the most serious reexamination of the US-Japan security alliance in decades.
Ever since three American servicemen based on the southern Japanese island of Okinawa were named last month as suspects in the rape of a 12-year-old schoolgirl, many Japanese have demanded change in the arrangement.
Some merely want a treaty modified so that Japanese police can investigate crimes involving American military personnel more easily. Others want the US military presence in Japan - particularly in Okinawa, where two-thirds of the approximately 45,000 American troops are based - curtailed. Still others want the Americans to leave altogether.
When President Clinton comes here next month for meetings with Prime Minister Tomiichi Murayama, the two leaders will likely issue a joint statement on the US-Japan security relationship.
But comments by officials in Tokyo and Washington suggest the two leaders won't announce any significant reductions in the deployment of US forces here or in the land area they occupy.
US officials have defended the security arrangement, calling it the bedrock of America's ''most important'' bilateral relationship. Furthermore, Washington does not want a controversy in Japan to inspire calls for similar changes in other countries, where US troops are based.
The furor over the rape has brought to the surface a number of Japanese concerns over the security arrangement. The concerns are all, in one way or another, about equity: the balance of rights, the balance of burdens, and the balance of forces.
Rights are the most immediate issue. The Status of Forces Agreement (SOFA), part of the mutual security treaty that the US and Japan signed in 1960, is intended to protect the rights of US service personnel stationed in Japan.
One provision specifies that if US authorities apprehend US personnel suspected of committing a crime in Japan, then the suspects must remain in US hands until they are formally charged by the Japanese. Japanese critics say this rule inhibits investigations, betrays a lack of confidence in Japan's legal system, and symbolizes an occupation-force mentality on the part of the Americans.
In the aftermath of the rape, figures such as Mr. Clinton and the commander of US forces in Japan have apologized for the pain the incident caused, even as the suspects remained on a US base.
US officials are now negotiating with Japanese counterparts to smooth what they describe as problems in the ''implementation'' of the SOFA, all the while insisting that the document itself should remain untouched.
Okinawans are the most upset about the rape, but that is not just because the incident took place there. They feel that the burden of hosting US forces is unfairly placed on them.
Historically, Okinawans consider themselves distinct from people who inhabit the main Japanese islands; their territory was forcefully incorporated into the Japanese empire in the latter part of the 19th century. In World War II, the Japanese military fought a terrible battle against Allied forces on the island, resulting in the deaths of as much as a quarter of the local population.
The perceived inequities continued after the war. The US ended its postwar occupation of most of Japan in 1952, but did not return Okinawa until 1972. The island forms less than 1 percent of the Japanese land mass, yet approximately 75 percent of the land the US occupies in Japan is in Okinawa. All told, the US controls roughly 20 percent of Okinawa.
In general, says Akiko Yui, editorial advisor at the Okinawa Times, people there wonder ''why should Okinawa continue to allow such a huge concentration of US bases on their soil?''
The US and Japan agreed in 1990 to discuss the return of 23 parcels of land in Okinawa, and so far 13 cases have been resolved. A Japanese Foreign Ministry official says the two countries are ''aware of the need to make developments on those issues,'' but concedes that the total amount of land involved is less than 2,500 acres. The official, who spoke on condition of anonymity, adds that discussions are also under way regarding three other US facilities in Okinawa, but says there are no plans to consider the return of more land.
Okinawans have traditionally felt that Tokyo officials have ignored their concerns, but there is growing recognition in the capital that the situation in Okinawa should be addressed. ''It's getting very serious,'' says Isamu Ueda, a parliamentarian whose constituency is near some major US facilities near Tokyo. ''I suspect that the atmosphere in Okinawa is stronger than what we feel in Tokyo. The government should do something.''
Although Japanese bureaucrats have echoed American pronouncements that the security agreement and the accompanying SOFA should not be revised, even conservative politicians have been notably silent. Indeed, with a general election expected in a matter of months, political analysts say that it is too risky for many leaders to come to the defense of the US-Japan security arrangement.
Perhaps Washington's biggest problem is the possibility that Japanese leaders will want to alter the balance of power between the two nations, or at least respond to public calls for change.
The 1960 treaty promises that the US will protect Japan and guarantees the provision of military bases to the US. The arrangement has been necessary for Japan in part because its own Constitution, initially drafted by US occupation forces, technically bans a military.
Some US analysts have seen the security arrangement as a de facto assurance that Japan will not rearm and again threaten world peace.
While there has been some debate in the US over the value of the security arrangement in the wake of the cold war, Japan has seen relatively little discussion. Says Hiro Umebayashi, an activist and researcher who has opposed some aspects of the US military presence: ''It is so evident that we have to discuss this relationship in this new international environment.''