What's down under, on high, and vital to arms control pacts?

As the United States and the Soviet Union prepare to begin destroying nuclear weapons to fulfill their latest arms control agreement, a highly secret complex in the Australian outback is taking on more importance to the West. It lies in the desert scrublands outside of Alice Springs, in some of the most unforgiving territory of this hard-bitten continent. But the isolation of the Joint Defense Space Research Facility - more commonly known for its location in Pine Gap - is, to US and Australian military planners, part of its beauty.

For this remote outpost provides a unique vantage point for staring down into the Soviet Union and determine whether the Kremlin is complying with arms control treaties.

``Pine Gap'' is the ``downlink'' for some of the most sensitive and important US spy satellites, providing the West with a wealth of intelligence data on Soviet missiles tests, radar emissions, and military communications. The Soviets are also well aware of the importance of Pine Gap; it is widely assumed that because of it and other joint US-Australian facilities, this country - even though it possesses no nuclear weapons - is a target of Soviet nuclear missiles.

Yet even that prospect has not dissuaded successive Australian leaders of all political stripes from defending the existence of Pine Gap. Even the current Labor Party government, which is embroiled in trade disputes with the US, resists any efforts to use Pine Gap and four other joint military facilities here as bargaining chips.

``They are not bargaining chips. They aren't on the table at all,'' says a senior official of the Australian Ministry of Foreign Affairs.

Australian Defense Minister Kim Beazley echoes that view, arguing that Pine Gap and the other bases here are part of ``our shared interests in [safeguarding] Western values.''

Indeed, says Professor Desmond Ball, head of the Strategic & Defense Studies Centre at Australian National University, Pine Gap is ``central to the entire Australian-US relationship,'' and crucial to the West in pursuing future arms control agreements.

Mr. Ball, author of a forthcoming book on Pine Gap, says, ``You can't monitor Soviet compliance with present arms control agreements - and even more so, you can't monitor Soviet compliance with any future arms agreements - without Pine Gap.''

But why the Australian outback? Actually, there would appear to be few sites in the world as ideally suited to the task as Pine Gap.

With its eight radar domes tucked in a valley in the desolate MacDonnell mountain range, Pine Gap is in an electronically ``quiet'' area, notes Ball, with few electromagnetic signals that might interfere with the incoming data. Moreover, he notes, the site is so isolated there is virtually no possibility that any foreign agent could get close enough to intercept the data beamed down from satellites and thus determine the extent of Western monitoring capabilities.

The entire electronic ``footprint'' of the satellite-to-earth transmissions falls well within the Australian outback. Neither Soviet nor East-bloc diplomats are allowed to travel to the area, and Australian intelligence agents monitor each visitor flying into Alice Springs or renting a car at the town's airport.

The airport is a busy one: At least twice a week, giant US C-141 Starlifter transport planes haul tons of magnetic tape back to the US for analysis by the National Security Agency at its Fort Meade, Md., headquarters. There is also a radio link between Fort Meade and Pine Gap.

The US Central Intelligence Agency runs the facility for the US. Australians makes up half the staff, however, and the Australian Security and Intelligence Organization shares fully in the intelligence picked up at the facility. ``We have no complaints about the level of cooperation and sharing,'' says Mr. Beazley.

Some people do have complaints, however. Two Australian legislators elected on a nuclear disarmament platform have called for the removal of Pine Gap and the other joint facilities on grounds they enhance the US military capability while unnecessarily making Australia a nuclear target.

``The verification role is a smoke screen,'' says Sen. Robert Wood of the Nuclear Disarmament Party. He claims Pine Gap spends only about 5 percent of its time monitoring treaty compliance (Ball says the figure is at least 40 percent). ``The analogy I use is that you don't justify the existence of a police force because they can also supervise parking. And you don't justify Pine Gap or Nurrungar [satellite control station] just because they can also be used for verification,'' argues Senator Wood.

For now, however, those holding such sentiments seem to be in a distinct minority. A recent Australian poll found that 67 percent of those responding favored having a defense relationship with the US. Forty-two percent favored the presence of the joint bases on Australian soil, and 37 percent opposed them.

Monitor correspondent David Clark Scott contributed to this report.