“It is hard to pin down,” notes Halik Kochanski toward the end of her enormous, but eminently readable, history of resistance to German occupation during World War II, “why certain people chose the path of resistance . . . . [T]he resisters themselves often give unsatisfactory responses: ‘one had to do something’ or ‘one just did what one could.’ ”

Perhaps that is because the experience was, in retrospect, so strange, so out of time and place. Ms. Kochanski, a British historian, quotes Jean Cassou, a resistance leader in Toulouse who remembered this “as a unique period . . . impossible to relate to or explain, almost a dream. We see . . . an unknown and unknowable version of ourselves, the kind of people no one can ever find again, who existed only in relation to unique and terrible conditions, to things that have since disappeared, to ghosts, or to the dead.”