IN explicating complex technical and scientific matters for the general public, tension between truth and clarity is a permanent feature. Doing justice to truth often requires arcane detail which defeats clarity. Analogy with familiar instances and omission serve clarity but unless judiciously practiced doom truth. The task is to craft a careful balance between the two: omit without misleading, explain without boring.

In his earnest effort to explain the strategic, scientific, technical, operational and military aspects of "Star Wars" to the general public, Robert Jastrow sadly fails to achieve this balance. As a result there is real risk that this valiant but hasty little book will mislead rather than inform, confuse rather than clarify.

The main part of How to Make Nuclear Weapons Obsolete consists of 140 pages of which 26 are taken up with pictures of dubious relevance, and another 20 or so with historical or technical anecdotes largely unrelated to the topic of the book. Given the unusually large print, Jastrow seems ab initio doomed to resorting to sweeping generalities, unexamined assumptions, and incomplete analyses of the various aspects of "Star Wars." Since he has given himself fewer than 20,000 words to explain such a complex topic, he has not managed to avoid these problems. The editing has not helped: The book is replete with repetition and suffers from innumerable internal inconsistencies, some trivial or even amusing, some fatal to the case in favor of "Star Wars" that the author is trying to argue.

One of the more serious inconsistencies comes early on: In a single page (15) the author tells the reader that "Star Wars" is intended "to put a shield between the United States and its enemies to protect us from their deadly weapons" and to protect our nuclear missile force from a Soviet attack so that "we will be able to strike back with our nuclear weapons." At this juncture the non- expert reader must be already hopelessly confused: It is public knowledge that the U.S. can hit back after a Soviet attack with the thousands of nuclear weapons we have on invulnerable submarines hidden in the oceans, so we don't need to protect our land- based missiles to do that. Second, protecting land-based missiles is a totally different task than "protecting us from (the enemy's) deadly weapons." In the first case an imperfect land-based defense may do the trick. But "protecting us" i.e., our population, our cities and industry, requires an absolutely perfect defense. The Russians have almost 10,000 intercontinental nuclear warheads. Even if the "Star Wars" defense were 99 percent efficient and 100 percent reliable, 100 of them would still sneak through. That means many tens of U.S. cities destroyed. What kind of protection is that?

What Jastrow omits to add is that the proposed "Star Wars" system would not intercept Soviet nuclear explosives carried by aircraft or cruise missiles or clandestinely introduced into this country. A large nuclear explosive is about the size of a garbage can. If thousands of tons of marijuana and other controlled substances enter this country illegally every year, why not garbage-can-sized nuclear bombs about which "Star Wars" can do nothing? Is this protection?

This pattern of glibness and incomplete examination dominates the technical arguments of the book as well: Jastrow describes with unbounded enthusiasm the placement of anti-missile weapons on satellites orbiting around the earth without mentioning that they can be, as Edward Teller is quoted as saying in the April 4, 1983 Christian ScienceMonitor, "destroyed at one-tenth the cost of placing them there." Neither does Jastrow have space apparently to examine the problems that the endless array of cheap, easily deployed countermeasures would cause to the "Star Wars" operations. His treatment of the decoy problem for example is cursory and incomplete, bordering on science fiction: He fails to consider the problem of anti-simulation (making a real weapon look like a decoy) and the fact that many American physicists have already thought of technical ways to frustrate his suggested solutions to the decoy problem.

SUCH CRITICAL omissions abound in the book. Nowhere does Jastrow mention the very serious problem of the electromagnetic pulses, generated by nuclear detonations, and their ruinous effects on the immensely complex electronics of the "Star Wars" defense. There is not one word on the entire issue of battle management (how to command and control the complex system of satellites, weapons, sensors, and computers that must recognize and engage the Soviet weapons during and after their launch), which the technical experts consider the most difficult component of "Star Wars" and with good reason: How can one ever make sure without testing under real combat conditions that the computer programs that must govern the "Star Wars" operations -- programs that could be up to one hundred million lines long -- will not have fatal bugs in them?

But if the list of omissions is large, the list of Jastrow's inconsistencies is larger: for example, on page 41 he tells us that "smart bullets," his preferred kill mechanism, can easily intercept nuclear warheads; on top of page 92 he tells us that it's not so easy after all! On page 104 he calculates that 100 satellites would be enough to wipe out 1,400 Soviet ICBMs. On page 129 he tells us that each of these satellites can destroy 14 Soviet ICBM's in flight. But then in order to destroy 1,400 Soviet ICBMs during their 300-second-long boost-phase, all 100 of these satellites would have to be over the Soviet Union at the instant the Russians were launching their attack, otherwise they couldn't shoot at their targets. But such concentration would be foolish on our part, because the Russians would wait until the cloud of 100 satellites would get beyond their horizon and then at their leisure -- since it would take the satellites at the very least 90 minutes and probably much longer to come back -- launch all their missiles.

Finally the book contains a number of red herrings easily recognized by a scientist but which would probably be swallowed whole by the unsuspecting general reader. Take the case of particle beam weapons: Jastrow argues that the accelerators needed for such weapons would be lighter than previously thought, as if their weight were their fatal flaw. Not so. The problem is that charged particle beams cannot be aimed either in outer space, or inside the atmosphere, over distances greater than a few thousand feet, and that neutral beams are useless, first because they cannot be aimed since they cannot be "seen," and second because they can be countermeasured trivially.

Robert Jastrow has written a deeply damaging book. Its injudicious advocacy of a given policy option, unsupported as it is by fact and thorough analysis, could raise serious doubts in the public mind about the objectivity and reliability of scientists as sources of information helpful to the making of sound public policy choices. This, in the long run, is the most undesirable aspect of this book.