biography, autobiography, memoirs : BEFORE THE WALL Berlin Days, 1946-1948<i> By George Clare (Dutton: $18.95; 288 pp.) </i>

George Clare, author of the well-regarded memoir “Last Waltz in Vienna,” spent two postwar years as a military officer in Berlin interviewing former Nazis in order to prevent them from regaining positions of authority. It wasn’t exactly rewarding work--with four occupying powers, it took an enormous amount of energy to get anything done--but the interlude obviously nudged Clare toward the introspection that war makes both difficult and necessary.

“Before the Wall,” at bottom, is about mixed allegiances: the conflicting emotions of an Austrian-born Jew in a British army unit attempting to come to terms with Germans who were responsible, to some degree or other, with the near-extermination of his people--including his parents.

For all that inherent tension, however, “Before the Wall” is relatively thin gruel. Clare’s work at the British Control Commission for Germany brought him in contact with numerous unsavory characters and culminated in a trip to Spandau prison to interview a former leader of the Hitler Youth, but Clare’s role is usually only that of functionary. Occasionally, he is accused by distant superiors of being too quick to see vestigial Nazism, but readers are more likely to see him as being, if anything, too slow in that regard--Clare is obviously fond of Berlin, having found the city in 1938 to be much more hospitable to Jews than was Nazi Vienna.

In fact, the real adversary in the book is neither memory nor Nazism but the Soviet Union, for while the Germans had little choice but to cooperate, the Soviets were intent only on advancing the cause of Communism. “Before the Wall” is nicely written and captures the flavor of post-war Berlin, but it’s not, as the publisher quotes one unidentified reader as saying, “a Berlin classic.”