TV's close-up on Strategic Defense Initiative -- a public service

Understanding ``star wars'' may be the intellectual challenge of the decade. If so, then Visions of Star Wars -- A Nova/Frontline Special (PBS, Tuesday, 8-10 p.m., check local listings) is essential viewing for citizens who are determined to meet the challenge. It offers two hours of background on President Reagan's Strategic Defense Initiative (SDI), filled with just about everything you ever wanted, or didn't want, to know about SDI.

Starting with the thinking behind Mr. Reagan's March 1983 decision to go ahead, the program tries to explain American disillusionment with the 1972 Antiballistic Missile Treaty between the United States and Soviet Union, the fears of a first strike of both the Soviet and American sides, the research being done on weaponry (including the new X-ray laser technology) and the actual hardware, the various motivations behind the SDI, and a look at its future.

Written, produced, and directed by Graham Chedd and Andrew Liebman of the Chedd-Angier Production Company, this first ``Frontline-Nova'' coproduction uses Bill Kurtis as narrator and special correspondent. Of course, there's also Judy Woodruff serving as anchor.

The main work, however, was done by the producers, who interviewed most of the scientists involved and visited key research sites.

Viewers will need to be prepared for a lot of high-tech terms, such as ``electro-magnetic launchers,'' ``radiation detectors,'' ``particle beams,'' ``space mines,'' ``free electrons,'' ``smart bullets,'' ``sensing satellites,'' ``anti-weapons.''

They should also be prepared for a lot of questions: Is it possible to produce a defensive system that is invulnerable and also cost-effective? Is Edward Teller's dream of a third-generation nuclear weapon just a fantasy? Can America afford not to experiment with SDI?

Despite the show's diligence in bringing together all the available facts, the answers are left for viewers to decide for themselves, as best they can.

``Visions of Star Wars'' is an exciting, if slightly overlong, electronic seminar, staffed with professors who know how to stimulate the thinking of the their students with such highfalutin, optimistic phrases as ``peace shields'' and ``magic shields.'' The show seems to make an earnest attempt to balance points of view so that all sides of the controversy are given a hearing. But it is inevitable that some partisans will insist their side has been slighted.

This program, however, represents a landmark (or should I say spacemark?) in public-service television. It seizes the ``high frontier,'' examines it in detail, and then turns it over for the American public to consider thoughtfully. Interview with the interviewer

The man who interviewed all the scientists who appear on ``Visions of Star Wars'' wants viewers to appreciate how enormously complicated any defense against nuclear missiles would necessarily be.

Reached by telephone, Andrew Liebman, co-writer, co-producer, and co-director of the special, tells the Monitor his research led him to the conclusion that ``SDI is really quite a long shot, but it is probably worth doing the research to be sure we keep up with the Soviets and look for alternatives to deterrence.

``. . .By recognizing that it is such a long shot,'' he continues, ``maybe we will also not lose sight of the fact that we must get along with the USSR . . . .''

Does Liebman believe the Russians are researching their own star wars?

``It's quite clear they are doing laser research which is every bit as threatening to us as our research is to them.''

At one point, the program suggests that SDI research may be a bit of a boondoggle. ``We are not saying `boondoggle,' but people should be aware that there are some very powerful incentives to be involved in SDI research that go beyond its feasibility.'' Some of those incentives: politics, profit, academicfunding.

Why are the Soviets so obsessed with stopping SDI?

``The Soviets are a military superpower, not an economic superpower, and they fear that if American technology is unleashed in the area of SDI, then the US will move past them in technology, an area they cannot match. And it would be so fantastically expensive for them, it would divert funds from essential domestic programs in the USSR. Some people in the US feel that SDI may be a valid form of economic warfare.''

Liebman, who interviewed Dr. Teller, thinks the physicist has great doubts about how his contribution to science will be viewed historically. Liebman thinks Teller would like to see a device come out of his work that would undo the damage caused by the threats posed by the H-bomb -- that he would like to help create a focused nuclear weapon that could be directed at a single target. That is what the X-ray laser reasearch aims at.

One of the suggested, although seemingly unlikely, ideas put forth at the show's conclusion is that the US and USSR share their technology in a defense system. ``Barring that, it is probably good for us to look into our technological bag of tricks to see what we can come up with,'' Liebman says. ``On the other hand, if we put all of our hope in technology, we may pass up diplomatic and political accommodations which might be the only thing that can save us.''

Did the producers' nine months of research for the program result in some new attitudes toward SDI?

``Both Graham Chedd and I came away with the sense that any defense against missiles is unbelievably difficult. We believe it will take something out of science fiction -- something as radical as, say, an antigravity force field, some physical principle that nobody even knows exists today -- to solve the problems. But, short of that, you are always going to have an overwhelming advantage of offense over defense.''

Shortly after our conversation, Liebman called back. ``In case I didn't stress this enough, I'd like to add one thing,'' he explained. ``If we do deploy what we can build, we might be a lot worse off than we are today; the world might be a lot less secure. Cooperation and understanding with the Soviets is still necessary so there will be no mixed signals.''