Soviet political fishing in South Pacific may net more clout. Some fear military influence will follow economic agreements with island nations

Warnings of a growing Soviet presence in the Pacific Ocean conjure up images of warships steaming past docile islanders fishing in lagoons. Perhaps in the North Pacific - which now hosts the largest of the Soviet fleets - the picture has some validity. But not in the South Pacific. It's been decades since a Soviet surface warship sailed south of the equator here.

The Soviet challenge in the South Pacific, says Australia's Defense Minister Kim Beazley is ``political, not military.''

Zbigniew Brzezinski, national security adviser to former US President Jimmy Carter, picked up a drum last week that several visiting United States government officials have pounded in the past year. He warned that ``political influence is the first step toward military influence'' and the Soviet long-term goal of removing US military facilities and port access in the region.

``One of the hallmarks of Russian policy is its persistence and prudence - a gradualist approach,'' Dr. Brzezinski said last week at a conference here on ``Soviet Ambitions in the Pacific.''

In the last three years, Soviet foreign policymakers have displayed greater astuteness in the region. As a result, the Soviets enjoy unprecedented political and commercial credibility with South Pacific island nations. Soviet successes include:

The signing of a $1.5 million fishing rights agreement with the tiny country of Kiribati in 1985. The contract has since lapsed.

A $1.5 million fishing agreement signed with regional maverick, Vanuatu, in 1986. This pact also gave the Soviets their first shore-leave rights and gave the state airline, Aeroflot, landing rights.

In 1987, the Soviets made diplomatic hay by signing (initially with qualifications) the South Pacific Nuclear Free Zone Treaty, banning testing and waste disposal.

To a large degree, Soviet influence has grown by exploiting the faux pas of the US and antinuclear sentiments in the region. For example, American tuna boats fishing illegally within the island nations' economic zones have significantly undermined US relations in the region. The US refusal to sign the Nuclear Free Zone Treaty came on the heels of New Zealand's denial of port access to US naval ships refusing to specify whether they carried nuclear weapons.

The Soviets have used these disagreements as opportunities to foster closer cultural and trade ties. They have extended trade and fishing agreement offers to Fiji, Tonga, and Papua New Guinea. Although most have not taken up these offers, they're now listening.

``The ice was broken [with the Kiribati agreement], and Soviet trade missions are at least being received by countries which have been hesitant about receiving trade missions in the past,'' observes Richard Herr, a political science professor at the University of Tasmania.

Next month, a Soviet trade delegation plans to visit Papua New Guinea. Already a small amount of trade and student exchanges are under way between the two nations, and Soviet lecturers may soon visit. But Papua New Guinea is not naive, says its Deputy Prime Minister Julius Chan.

``You don't have to worry about some real or imagined Satan jumping the backyard fence... [We] are capable of tempering what you may see as Pacific idealism with some good old-fashioned Western pragmatism,'' he said.

Western allies have overreacted to Soviet progress in the South Pacific, says Greg Fry, a political science professor at Australian National University. Soviet influence has grown modestly, but from a low base.

``If you're looking at great power involvement in the region today, its the US, France, Japan, China, and very much last in the race is the Soviet Union.''

Indeed, it can be argued that the tide of Soviet influence in the South Pacific is already ebbing. The fishing treaty with Vanuatu lapsed in January. Soviet Embassy officials in Canberra say renegotiation efforts are under way. But Australian diplomatic sources say Vanuatu hasn't responded yet, and may not do so at all .

Meanwhile, the storm cloud over US tuna fishing in the region is dissipating. After two years of negotiations, a fisheries treaty between the US and 15 Pacific Island states was signed and ratified by Congress late last year. The treaty effectively doubles US annual aid to the region. The State Department is boosting staff and setting up two new diplomatic missions in the region.

But Dr. Herr doubts the Soviets will simply pack up and leave now. Soviet leader Mikhail Gorbachev's Vladivostok speech of 1986 explicitly expressed Soviet regional interest. Herr notes the Soviets are posting a much higher caliber of diplomat here now. And Moscow has established a new South Pacific Affairs bureau in its foreign policy office. Herr predicts the Soviets will incrementally build their connections and presence.

A military facility is unlikely since the strategic value is minimal. But there are economic incentives for the Soviet to cultivate ties with the Oceania nations. For fishing, and the potentially vast seabed mineral resources, the Soviets would like to maintain access to 200-mile economic zones surrounding the Pacific nations. Gold is developing as a major regional resource. And, more recently, equatorial islands have been eyed as low-cost launch sites for putting satellites in orbit.