Gazing out the open cargo doors of the Huey flying over Phouc Long Province, boyish-looking Specialist 4 Robert Pryor took in an endless landscape of mountains, meandering rivers and rolling hills covered with dense evergreen vegetation, bamboo thickets, and triple canopy tropical broadleaf forests. The forbidding wilderness had an odd virginal beauty. It was also one of the most dangerous places in South Vietnam. This sparsely populated highland plateau, nestled along the Cambodian border...