It’s a Wonderful Reich : FATHERLAND <i> By Robert Harris (Random House: $21; 338 pp.)</i>

One of my favorite books growing up was a dog-eared paperback novel called, “If the South Had Won the Civil War.” Those two magical words-- what if --shattered the aura of inevitability that always made the past seem so dead. They showed me that real history was something alive and unpredictable.

“Fatherland,” the first novel by Robert Harris, a political columnist for the London Sunday Times, is predicated on another historical travesty: What if the Nazis had won World War II?

It’s Berlin, 1964. Adolf Hitler is 75 years old and still going strong. His dominion reaches from the Rhine to the Urals; the Soviet Union ceased to exist in 1943, and only an uneasy Cold War with its sole nuclear rival, the United States, keeps the Greater German Reich from getting any greater.

England is a Nazi satellite. Oxford has become a prestigious SS academy, and Winston Churchill lives quietly in Canadian exile. King Edward VII, who in real life abdicated his throne and whose pro-German sympathies are now well known, occupies Buckingham Palace with Queen Wallis beside him.

The novel’s finest conceit is the physical transformation of Berlin. Hitler and his personal architect, Albert Speer, always planned to remodel the capital, and Harris belatedly brings their blueprints to life. The skyline is dominated by Speer’s thousand-foot-high Great Hall, visible for miles, large enough to hold 180,000 people. Buses filled with Japanese tourists roll along a 400-foot wide Grand Avenue and pass under a monumental Arch of Triumph to emerge at Hitler’s Palace. Souvenir-shop windows are filled with framed photos of the Fuhrer, the famous Cecil Beaton portrait taken during the ‘50s--Hitler’s favorite.

At first, Harris’ exotic setting is more compelling than the conventional murder-mystery plot. There’s the corpse (a retired Nazi official), the jaded investigator (an SS Sturmbannfuhrer with heart), the feisty female reporter (an American expatriate), and behind everything an evil mastermind (guess who).

The initial investigation hints at some darker crime buried further in the past, and homicide detective Xavier March, who conceals beneath his black SS uniform a conscience worthy of Philip Marlowe, isn’t afraid to dig. “His duty,” Harris writes, “is to the dead.” March thinks he’s stumbled across a financial scandal involving top Nazis and valuable art stolen from wartime Poland, but we know something he doesn’t: that worse crimes were committed in occupied Poland during the war than art fraud. March is in over his head.

The reader will immediately sense something off about this Nazi dystopia. There is no antisemitism. In fact, there are no Jews at all. When March finds a photograph of a Jewish family who lived in his apartment before the war, he feels uneasy. As far as he knows, all German Jews were peacefully “evacuated to the east during the war.” March gets his history from Goebbels’ Ministry of Propaganda, which puts him at a disadvantage. Still, the faded photograph haunts him. March doesn’t realize it, but his simple art-fraud case is about to turn into every detective’s Holy Grail: the undisputed Crime of the Century.

The real Hitler had no illusions about how the Final Solution would play if widely publicized, and so from the start every effort was made to keep it quiet. Evidence was routinely destroyed. Hitler himself never signed his name to any actual order, so if he’d won the war, might not the Holocaust have been the perfect crime? Since the reader knows the truth before March does, the plot is ingeniously reverse-engineered to keep it suspenseful. Will March uncover the truth before he is shipped off to a Gestapo prison?

There’s an added twist: March’s inquiries jeopardize the crowning achievement of Hitler’s three decades in office: world peace. Newspapers have just announced that the U.S. President, seeking detente with Germany and an end to the Cold War, will soon make a historic visit to the Reich to meet with the Fuhrer. Revelations of a Holocaust would make appeasement impossible. (In one of the novel’s many clever jokes, there is a Kennedy in the White House, but it’s not John. It is Joseph P. Kennedy, J.F.K.’s father, who was known in real life for his anti-British and pro-German leanings right up to the war.)

This is not the first novel to imagine an alternate outcome to World War II. There are Philip K. Dick’s “The Man in the High Castle” and Norman Spinrad’s “The Iron Dream.” The genre is so extensive that there is even a short-story anthology entitled “Hitler Victorious.” Len Deighton’s masterful “SS-GB,” a chilling tale of England under Nazi rule, is closest to “Fatherland” in spirit. Deighton is a better thriller writer, and a better historian, but Harris shows promise.

“Fatherland” is already a bestseller in England, and has been acquired for publication in 11 other countries, but not in Germany. Some Germans, apparently, think it is anti-German. Harris’ United Nazi Europe does sound at times like a sinister parody of the current scene. “People drove German cars, listened to German radios, watched German televisions, worked in German-owned factories, moaned about the behavior of German tourists . . . while German teams won every international sporting competition except cricket, which only the English played.”

Germans needn’t worry. “Fatherland” doesn’t come close to doing to their country what Michael Crichton’s incendiary “Rising Sun,” for instance, does to Japan. In fact, “Fatherland” is hardly about Germany at all. Harris’ middle-aged National Socialist state bears little resemblance to the muscular brutality that was German fascism in its prime, and the plot’s peculiar requirement that antisemitism be all but invisible robs Nazism of its terrifying uniqueness. This particular Berlin, with its monumental architecture, gray bureaucracy and constant surveillance, feels more like Brezhnev’s Moscow (or, for that matter, like Honecker’s East Berlin) than Hitler’s dictatorship. It’s communists who should feel insulted, if there are any left.

Harris may be suggesting that all forms of totalitarianism are the same, which is neither original nor true. But surely this is taking the novel too seriously. “Fatherland” works fine as a sly and scary page-turner, and for those of you who can’t imagine a summer at the beach without at least one good Nazi thriller--and who can?--then Xavier March is the SS man for you.