The Washington PostHUNDREDS of men were pinned down in France’s Argonne Forest, surrounded by the enemy. They’d been fighting furiously for six days, and now they were taking friendly fire from their would-be rescuers.It was 1918, and a troop of Allied soldiers who would later be called the “Lost Battalion” had one last hope: A pigeon named Cher Ami, who carried a note with the soldiers’ coordinates. When he arrived at headquarters, Cher Ami had been blinded in one eye by shrapnel, was nearly missing a leg and had been shot through the breast by a German bullet. He had flown 25…