Gustavo Petro, Colombia’s first leftist president, ran for office on a platform of reversing many of the country’s most hated policies, including the decadeslong war against Marxist rebel groups that left hundreds of thousands dead.

Gustavo Petro, Colombia’s first leftist president, ran for office on a platform of reversing many of the country’s most hated policies, including the decadeslong war against Marxist rebel groups that left hundreds of thousands dead.