UNDISCLOSED, Lebanon — The Army recruiter thought the well-dressed young man was lying. After all, the yarn this man spun, after walking into the recruiting office in Baltimore, sounded like pure nonsense. All kinds of honors at Swarthmore College. Top of his class at Columbia Medical School, and now into his fourth year of the elite, seven-year residency program at Johns Hopkins in neurosurgery. He claimed to speak both English and Korean fluently. Yeah, sure. This young man wanted to be a Green Beret? An enlisted man in the U.S. Army? Bringing home a base pay of $32,000 a year? The recruiter was polite; they always are. But he insisted the recruit come back with his diplomas to prove he was who he said he was. When proof was provided, the recruiter tried to convince the aspiring brain surgeon to join the U.S. Army Medical Corps as a physician. No dice. He had a different adventure in mind. Today, that young man is a sergeant. He is a Green Beret in the U.S. Army, the absolute crème de la crème of the 1% who chose to serve in the military. He carries an M4 assault rifle to work, can jump out of a C-130 cargo plane, fast-rope off a Black Hawk helicopter, and is an expert on small unit tactics. He can avoid capture, resist interrogation, and train a guerrilla force behind enemy lines. There’s...