As a young military officer at the height of the war on terror, Lt. Ron DeSantis was often seen running on the beach of Guantánamo Bay and along its ridgeline, encircling Camp America. It was a chaotic time at the U.S. military detention facility in Cuba, and as an ambitious Navy lawyer, DeSantis was positioned to witness history up close. He arrived at Joint Task Force Guantanamo in the spring of 2006 as its leaders were grappling with multiple challenges and global scrutiny. Aggressive tactics were adopted to break a hunger strike. An armed clash erupted between detainees and a...