THE WALL WENT UP in August of 1961 and a few months later in Berlin, during that cold winter, perhaps the coldest winter of the cold war, the Americans, the British and the West Germans became extremely interested in those who could make it with ease through Checkpoint Charlie.

One who crossed back and forth between East and West with both ease and some regularity was David Plummer, an illusionless American employed by a British firm to sell lubricants to the East Germans. Plummer is one of the two principal protagonists in W. T. Tyler's superb novel, The Man Who Lost The War .

Superb is an adjective that should be used with extreme caution, if at all, but I'll hang it on the pseudonymous Tyler's first novel because he has written a spy tale with fine characterization, almost faultless dialogue, a cumming, twisting plot, and a remarkable, nearly total sense and recollection of both time and place.

Plummer is an ex-CIA agent, pushing 40, who once worked out of Prague and Vienna until an accident cost him both his job and his love, the latter a cool, rather dim, impossibly nice British beauty whom he again encounters in Berlin where "she treats him like an old friend, an elderly uncle returned from the antipodes after a long absence."

On a routine business trip to Rostock in East Germany, Plummer is approached by Strekov, a KGB agent who doesn't for a minute believe that Plummer is no longer with the CIA. Strekov is in Rostock because of a defected British radio technician who accidentally has discovered the true identity of a highly placed double agent in Britain's M16 whose code name is Solo. On Moscow's orders, the British technician is killed.

Strekov puzzles yet fascinates Plummer. Strekov's face has a quality to it htat repels him. "It was a face," Plummer decides (in a passage that the publisher insists on misquoting on the back of the jacket), "that seemed to deny the human element, that expressed a sort of isolation that in banishing doubt or uncertainty, banished everything else as well. It was a look assumed by most searchers after truth or absolutes, the vacuum that infinity leaves behind when it terrorizes the temporal world. Some priests had it; so did most anarchists; so did men left too long at sea in open boats."

Eventually, Strekov begins passing information to Plummer in East Berlin. It is vital information concerning Soviet missiles. Plummer hesitantly turns it over to the CIA, but the CIA is greedy. It wants more. And it also wants to control Strekov because it suspects that through him it can finally trap Solo, the double agent the KGB has planted in the upper reaches of British intelligence. What puzzles the CIA, however, is why Strekov is passing the information. He asks for nothing in return, neither money nor sanctuary.

When the CIA insists that Plummer bring Strekov out of East Berlin, Plummer snaps: "What are you trying to do? . . . What the hell's on your mild? Run him until he is no good anymore, bring him over, debrief him, find out whether the urge is suicidal or just manic-depressive because he hasn't been promoted in ten years? What are you going to do, wind him up, send him back in and let the crows take the rest?"

Tyler smoothly peels back one layer of deception after another until at last all is revealed and all is resolved. And if there are no winners, only losers, Tyler seems to feel that that is pretty much what the spy business is all about.

The British spies for once come off no better than the Americans. During the war, Tyler tells us, they had killed "Germans, Italians, Greeks, Albanians, and Yugoslavs as efficiently as the snipe, blackgame, and golden plover" they later hunted in Northumberland.

"They had all done the same things during the war," he writes, "a war without moral limit, which had claimed their consciences, their promise, and their youth . . . In disappearing one by one back into the world of British intelligence, they had rediscovered themselves in a war in which moral absolutes had vanished once again. It was the only world they knew."

The book takes its title from a piece of doggerel that Plummer notices in an East Berlin coffeehouse. A picture of an American battle unit entering East Berlin has been tacked up and under it is written:

I never learned his name;

We never knew his corps;

Dead in the Neisse that day;

The Man Who Lost the War.

Tyler's novel is an extremely well-written, sardonic romance about the spy business as it was nearly 20 years ago. It is also a long but by no means leisurely book, and one to be savored.

Another first novel is James J. Nordhoff's Eastwind/Westwind . While written with competence and even a certain amount of flair, its plot has been just a bit too wildly devised.

The president of the United States gets a mysterious phone call that tells him he has 10 days in which to nuke the Russians and make it look as though the Chinese did it. Otherwise, half of the population of San Francisco's bay area will be wiped out.

To make sure the president doesn't think that this is just some nut on the line, the caller has already blown up a high performance government plane and patched himself into the president's private phone, a technical feat that is supposedly impossible.

There are five persons in the Oval Office when the call comes through and only they can stop the impending disaster. The death of a longtime American agent in Vienna soon leads some of the federal sleuths back to the Nazis in the last days of World War II. The Nazis, of course, just might have discovered the wherewithal to make good the threat against the bay area.

Suffice it to say, half of San Francisco'spopulation doesn't get zapped, but it's a close call -- close enough to keep the suspense going right until the last page. The president almost has his finger on the button when the whole thing is resolved. Another Nordhoff tell us the president is politically unpopular. It's not at all hard to understand why.