The Japanese government welcomes the new Reagan administration proposal for the elimination of medium-range nuclear missiles in Europe and Asia, a foreign ministry official here says. The proposal to the Soviets incorporates Japanese government objections to an earlier formula. That plan would have eliminated the missiles in Europe but called for only 50 percent cuts in Soviet SS-20 missiles based in the Soviet Far East. Both Japan and China reportedly told US arms control adviser Edward Rowny earlier this month that they were unhappy with any decoupling of European and Asian security concerns.
``Our position has been that the lowest possible level of intermediate-range nuclear forces should be achieved while appropriate considerations should be paid to security interests in Asia,'' a Foreign Ministry official said. ``From this point of view, we think that this time the US proposal has taken our position fully into consideration.''
The US offer seeks 50 percent cuts in medium-range missiles each year for three years, with ``concurrent proportionate cuts in Asia.'' This would lead to elimination of such weapons by 1990.
The initial Soviet proposal, made by leader Mikhail Gorbachev on Jan. 15, excluded eliminating Soviet missiles based in the Far East. According to NATO estimates, there are 171 mobile SS-20 intermediate-range nuclear missiles located in Asia.
The Soviet Union has previously argued that the Far East-based missiles are meant to counterbalance US nuclear capability in Asia, and implicitly that of China. A recent Soviet commentary, published by the press agency Novosti, vowed that ``Washington will never make the USSR dismantle the SS-20 missiles in eastern regions of the country in return for the elimination of the American medium-range missiles in Europe.''
Soviet officials in the past have justified this posture by pointing to the US deployment of nuclear-capable submarine-launched Tomahawk cruise missiles in the Pacific and to the stationing, since last year, of F-16 fighters at an airbase in northern Japan. Both the Tomahawk and the F-16 can be equipped with conventional as well as nuclear explosives. It is official US policy not to comment on the presence or whereabouts of nuclear weapons.
``If the Soviet Union suggests that some nuclear weapons are stationed in Japan,'' a Foreign Ministry official declared, ``we categorically deny it.''
``Their argument is totally irrational,'' the official contends, pointing out that the Soviets began deployment of SS-20s first, in the late 1970s. The recent stationing of F-16s and cruise-missile-equipped submarines in the region ``is part of a US effort to maintain and strengthen overall deterrence'' in the area.
The SS-20 missiles are also mobile and could be moved from Asia to Europe, a fact in favor of their total elimination in any INF agreement. Moreover, the Japanese official pointed out, the ``Soviet Union is quiet on their aircraft and other systems'' based in the Far East.
Nonetheless, the inclusion in the proposal of the Asian missiles undoubtedly makes the prospects of INF agreement more difficult.
``The Asian theater is much more complicated because of China and differences in the geostrategic situation,'' says Seizaburo Sato, a security expert and professor at Tokyo University. He says the Soviets may feel they have to rely on nuclear weapons against China because of inferiority to the Chinese Army in conventional forces. In that sense, he says, the Soviet position is comparable to that of NATO in Europe.
``A reduction in nuclear forces in Europe cannot be harmful to Japan,'' Professor Sato argues, ``even if nuclear forces [in Asia] are maintained.
``Logically speaking, Japan should not protest so strongly. At the same time, there is a deep fear of being isolated from the Western alliance and the US should be very careful.''