In 1941, the Jewish American writer and avant-garde icon Gertrude Stein embarked on one of the strangest intellectual projects of her life: translating for an American audience the speeches of Marshal Philippe Petain, head of state for the collaborationist Vichy government. From 1941 to 1943, Stein translated thirty-two of Petain's speeches, in which he outlined the Vichy policy barring Jews and other "foreign elements" from the public sphere while calling for France to reconcile with Nazi occupiers.

Unlikely Collaboration pursues troubling questions: Why and under what...