It will take a lot of talk to bridge US-Japan gap on defense spending

The Zenko Suzuki government has no intention of being pressured by the Reagan administration into a rapid defense buildup. Defense Minister Joji Omura has been instructed to tell his counterpart, Caspar Weinberger, in Washington this week that Japan will stick to its plans for a 7.5 percent ceiling on increased defense spending next year.

Government sources disclosing this information also said they did not expect a collision between the American and Japanese governments over Japan's defense spending. Rather, the outlook is for prolonged discussions between Tokyo and Washington, leading perhaps to a modest upward revision of current government guidelines for a defense buildup.

Japan, in other words, is not going to be stampeded by Pentagon talk of a "vulnerability window" during the next five years. Mr. Omura, in fact, is going to ask Mr. Weinberger what the basis is for American proposals aired at a working-level conference in Hawaii earlier this month, which, according to Defense Agency calculations, would require a 24 percent increase in the Japanese defense budget. (This year, Japan is spending 2.4 trillion yen or about $11 billion on defense. The 7.5 percent ceiling for next year means a maximum increase of 180 billion yen or about $818 million.)

At Honolulu June 10 to 12, Defense Agency sources said, American officials proposed that Japan increase antisubmarine planes to 125, destroyers to 70, and submarines to 24, whereas Japan's own defense buildup plan envisages 100 antisubmarine planes, 60 destroyers, and 16 submarines.

Washington also wanted Japan to have about 100 more interceptor planes than Tokyo had projected and to improve the war-readiness of its forces. Defense Agency sources calculated that the American proposals would require an increase of 24 percent in the defense budget for the first year; whereas Japan's plans call for completion of the buildup by 1987, the Americans wanted their own more ambitious targets to be reached in five years.

"We would like a more detailed explanation as to why the American side thinks their figures are more realistic than ours," said one Japanese official who participated in the Honolulu talks.

Japanese Defense Agency sources say they think the American proposals were "arguable but not unrealistic." Other Japanese government sources say the American proposals required defense spending so much higher than the Japanese had projected as to be completely beyond the realm of the achievable, given the realities of the Japanese situation.

These realities include: an overall budget that is 30 percent in deficit, continuing inflation, and the need to reduce government expenditures all aro und.