Was it Pericles who said ''Just because you don't take an interest in politics doesn't mean politics won't take an interest in you"? Or was it Trotsky? Or both? Neither one, it is safe to assume, spent much time reading historical novels, let alone historical crime novels. Today, however, they might, if only to see themselves repeatedly proved right.
Take a sufficiently murky period -- say Berlin in 1919 -- and even the most cynical hero is out of his depth once politics takes an interest in him. Detective Inspector Nikolai Hoffner, for example, thinks that he has seen it all. ''Christmas had brought nothing, except perhaps the truth about how the war had been lost long before the summer," he observes at the beginning of Jonathan Rabb's new novel, ''Rosa." ''Oh, and of course, the revolution . . . a thoroughly German revolution with documents in triplicate, cries from the balconies, demonstrations and parades, tea still at four o'clock, dinner at seven, and perhaps a little dancing afterward. . . . Shots had been fired, naturally, a few hundred were dead, but the socialists -- not the real socialists, mind you -- were straightening everything up."
