EARLY ONE morning in February 2012, as the Syrian army was pounding the besieged city of Homs into submission, artillery fire crashed around a building in the embattled district of Baba Amr. As rocket fire closed in, the handful of foreign journalists and activists who’d been using the building as a makeshift media center panicked.

Marie Colvin, the American correspondent for England’s Sunday Times newspaper, dashed into the street seeking escape. Outside she was struck by a rocket and died instantly. French photographer Rémi Ochlik, running at her side, was also killed.

The journalists’