It was the news the world breathlessly waited for immediately after the 9/11 terror attacks: a report of the first American troops on the ground in Afghanistan. All at once, the world’s attention focused on an iconic photo of those Special Operations Forces doing something no American military had done in nearly a century: They rode horses into combat. Horse Soldiers of 9/11 Film Trailer Their secret mission: secure northern Afghanistan by advising the warring tribal factions that formed the Northern Alliance. During the 2011 Veterans Day Parade on Nov. 11, a new monument to these men — and to...