Together with Abraham Serfaty, Sion Assidon is one of Morocco’s most prominent Jewish left-wing activists. Born in Agadir in 1948, he was arrested in 1972 as a member of a student group campaigning for democracy, charged with the crime of possessing anti-regime leaflets. He was sentenced to fifteen years, but the attention brought to his case by Amnesty International as a nonviolent “prisoner of conscience” contributed to his release by royal pardon in 1984.

A mathematician by training and a businessman by profession, Assidon was founding secretary general of Transparency Maroc, …