We examine as well the many contradictions of life in a combat zone. Our eyesight and hearing are sharp, our other senses keen. The water always quenches our thirst. The sky is bluer than we thought possible. And we’re with the best friends we’ll ever have. The good gets better, but the bad gets worse. We always have some minor eye or ear infection, our feet hurt all the time, and sleep is sporadic at best. The heat is sweltering, the cold bone-chilling. We’re constantly tense to the breaking point. And lonelier than we ever imagined…

Ultimately, because of the business we are in, expected to fight, suffer and die without complaint, we also cultivate this bond to call on when needed. At times, it means being ruthlessly hard, as at Balaclava in 1854. When the “thin red line” of the 93rd Highlanders were all that stood between the Russian onslaught and the British camp, Sir Colin Campbell commanded the regiment he loved, “there is no retreat from here, men — you must die where you stand.” At times, it means having compassion, as on Tulagi Island in the South Pacific in 1942. After an all-night attack, Marine Pfc. Edward “Johnny” Ahrens lay quietly in his foxhole. He’d been shot twice in the chest, and blood welled slowly from three deep bayonet wounds. Thirteen dead Japanese soldiers lay nearby; two others were draped over his legs. Legendarily tough Lewis Walt — later assistant commandant of the Marine Corps — gently gathered the dying man in his arms. Ahrens whispered, “Captain, they tried to come over me last night, but I don’t think they made it.” Choking back tears, Walt replied softly, “They didn’t, Johnny. They didn’t.”