CHAPTERS OF The Devil's Alternative end with a short sentence in a haunting passive voice. "Lunches were ill-digested," goes one, and your's may not sit quietly in the stomach either after finishing Frederick Forsyth's latest and alarmingly timely new novel.

As if President Carter doesn't have enough trouble already, he may soon be accused of orchestrating events to conform to the plot of Forsyth's book. The action that sets off the universe-threatening troubles in Alternative is an American embargo on grain sales similar to the one Carter ordered last Friday. If we're in for a two weeks anything like that which President William Matthew's nation edures, better look into buying real estate in a remote area--like Venus.

But for all its similarity to contemporary politics, Forsyth has not written a great book, nor as good as his first novel, The Day of the Jackal. Forsyth crafts plots, and he does so better than virtually any other thriller-writer around. Plots need people, however, and that is where the troubles start.

Forsyth could never create a George Smiley, the hero of John Le Carre's series that began with The Spy Who Came in From the Cold. However convoluted his adventures, Smiley provides an anchor for every Le Carre story because he is a real person--a troubled, depressed, aging spy. Forsyth deals in Supermen, plastic men whom we will root for but never really care about as human beings. He came closest in Jackal, with his portrayal of the man who tried to assassinate Charles De Gaulle; he failed outright in his two later novels, The Odessa File, in which Superman infiltrated a society of Nazi war criminals, and The Dogs of War, in which Superman directed a coup d'etat in a small African nation.

The hero this time is Adam Munro, a British spy working under cover in his nation's embassy in Moscow. Pretty straight arrow this Munro, all the right schools, the right background, except for a short, passionate fling with a Russian beauty during the Berlin crisis. But she "slipped back into the East through the last uncompleted section in the Wall, sad and lonely and heartbroken--and very, very, beautiful." Never to be seen again. Suuuuure.

FORSYTH MOVES THE action around the globe every few paragraphs until we learn that the Soviet grain crop has failed almost completely because the red bureaucracy fouled up. The folks in the Zil limousines, especially the Brezhnev-clone Soviet premier, Maxim Rudin, are not amused, and Rudin's Kremlin rivals want to use the crisis to get the old curmudgeon bounced. Back in Washington, Bill Matthews and Assistant for National Security Affairs, Stanislaw (read Zbigniew) Poklewski, and Secretary of State David (read Cyrus) Lawrence want to use the shortage to wring concessions out of the Russians.

And then there is Andrew Drake. A mild that Ukranian nationalism will be his cause for his fourth book. Perfect vehicles for displaying the author's well-known and rabid hatred of the Soviets, Drake and his crew of "freedom fighters" make the moves that turn the grain shortage into possible Armageddon. There is something disturbing about the terrorist-as-hero syndrome so pervasive in contemporary thrillers, but with writers struggling to match newspaper headlines, they seem compelled to have characters willing to use extremism in defense of their vision of liberty.

Not wanting to miss any big-new-story bases, Forsyth throws in the maiden voyage of the world's biggest oil tanker, the Freya, hauling one million barrels of crude into Rotterdam. Anyone who has ever read a book or seen a movie knows as soon as you hear "maiden voyage," you better reserve a seat on the lifeboat. The ship and the Kremlin and the Ukranians and the White House all begin high-speed confrontations and near confrontations as Forsyth builds the tension. Which he does brilliantly. He spends several paragraphs in each location and uses almost cinematic cuts, back and forth, the intervals growing shorter as the action grows more frenzied.

OF COURSE, there are the characteristic Forsyth touches that, despite his faults, make him a reliably entertaining read. An important Forsyth character would never deign to walk through the front door of a famous building; the author's knowledge of the innards of 10 Downing Street, the White House and, most impressive of all, the Kremlin, add immeasurably to the sense of reality. Superb mannered pillar of the English middle class. It is at first hard to understand what this man is doing among all these movers and shakers. We soon learn: "Andrew Drake, despite his Anglicized name, was also a Ukranian, and a fanatic." Forsyth decides Bond-like gadgets also appear in delicious profusion, including a personal favorite, the "flash-bang-crash grenades," which blind anyone looking at them, blow out their eardrums, and "cause a ten-second paralysis." Just ten seconds?

The climax does not disappoint. The activities surge to a wild crescendo with everything from the fjords of Norway to the world's fastest airplane integrated into the resolution. Forsyth has indeed fashioned a thriller, where--don't be deceived--the surprises keep coming until the very last page. If only he could portray a human being with the same verve and insight with which he calls forth a "short-barreled pump-action shotgun."