In the mid-1960s, before GPS and global tracking, a young man could walk into a shipping hall, sign a paper, and be bound for war by sundown. Roberto Loiederman did precisely that.One day, he was dropping acid in a legendary San Francisco apartment called Cave 7, moving among the era's most influential counterculture figures—including a turbulent friendship with Hunter S. Thompson. The next, he was on the deck of a freighter hauling napalm across the Pacific to Vietnam.With...