Bill Hudson hoped he'd see some action before World War II ended. He was a good swimmer, could shoot, and enjoyed explosives, so the United States Marine Corps put him through an early version of SEAL training. Then they gave him a gun, made him an infantryman, and spent months training him to invade an island: Iwo Jima. The island, they told him, would be easy to take. It was fewer than ten square miles and had been bombed for weeks. After quickly taking Iwo Jima, the Marines would move on to Okinawa, setting the stage for the coming invasion of Japan. Hudson landed with the first wave of...