Spies, Satellites and Sex : THE FIST OF GOD, <i> By Frederick Forsyth (Bantam: $23.95; 560 pp.)</i>

It’s difficult to tell exactly what Frederick Forsyth had in mind when he started “The Fist of God.”

He clearly wanted to write an op-ed piece of sorts, warning his readers about the dangers of nuclear weapons proliferation and the need for great powers to maintain a robust network of human spies, even in the post-Cold War era. In fact, just to make certain no one who reads the novel misses these points, Forsyth supplies an appendix in the form of an essay in which he spells them out.

“It is madness for the thirty most industrialized developed nations of the world, who dispose between them of ninety-five percent of high-tech weaponry and the means for its production, to sell these artifacts to the crazed, the aggressive and the dangerous for short-term profit,” he writes.

Fair enough. No one watching the gathering crisis in North Korea would be inclined to argue.

Forsyth’s devotion to the preservation of the secret agent’s brotherhood is a little harder to support in light of espionage fiascoes like the Aldrich Ames case. Outside of the genre novel, it’s not so clear that the intelligence gathered by human spies justifies the enormous cost. But since Forsyth clearly has friends in the brotherhood, his view is not surprising.

Forsyth apparently also wanted to write a technical history of the Persian Gulf War of 1991, and in this he succeeds brilliantly. Page after page is given over to lucid, thoroughly researched descriptions of the weapons systems and communications technology that won the war.

Among many other items, he gives the best concise explanation I have yet read for why the Patriot missile failed to stop most of the SCUD warheads thrown by Iraq at Israel and why, in the end, it hardly mattered.

To reach Israel, the Iraqis had to modify the SCUD supplied by the Soviet Union, adding range at the expense of payload. This jerry-building meant that the rocket tended to disintegrate as it descended toward its target.

The Patriot was programmed to respond to this confusion by seeking out and destroying the biggest piece of the SCUD it could see, which in most cases was the missile’s spent fuel tank. But the good news was that the warheads that got through were too small to cause much damage. The SCUD was largely a psychological threat, and the Patriot was largely a psychological response. It did its real job, which was to keep Israel out of the war and thereby preserve the coalition of Western and Arab nations arrayed against Iraq.

Forsyth chose to package all of this erudition in the form of a thriller, and in this he was somewhat less successful. The book has characters aplenty; it begins with the Tolstoyan three-page dramatis personae that lists only the important ones. But few of these characters are engaging and almost none have more than two dimensions. Forsyth’s idea of character development is to have one character read the resume of another, listing the schools and regiments he has passed through.

Human beings are not, in the end, as important to the story as governments and weapons are. Forsyth spends much of the first 50 pages discoursing on the late Gerald Bull and his advanced cannon technology. Only after this is complete does he get around to introducing his hero, an Arabic-speaking commando in the British Special Air Services.

Forsyth has fortunately not forgotten how to structure a plot. This one involves the conjecture that Saddam might indeed have developed a nuclear weapon just prior to Desert Storm, secreted it in a camouflaged mountain fortress, and prepared to fire at the advancing allied troops, using the big cannon technology developed quietly for Iraq by Bull. The successful prosecution of the war hinges on whether the Allies can find and destroy this weapon before the land war begins. Clever spies, communications satellites, reconnaissance technology and high-tech weaponry, as well as money and sexual wiles, are all bent to this end.

Readers who can remember the headlines from February, 1991, will know the outcome. But Forsyth spins a story so well that they will keep turning pages to find out exactly how it was done.