The Acid Vat of History

An enduring mystery of Moroccan politics is what happened to Mehdi Ben Barka. The former math teacher of King Hassan II became the country's main opposition leader, "the hope of his generation," as some reformers still call him. In Paris one evening in 1965, he vanished outside Brasserie Lipp. Now, more than three decades later, the truth may be coming out.

According to a detailed report by the Casablanca independent weekly Le Journal, based on the claims of a former policeman, five Moroccan agents trailed Ben Barka as...