From the air, the Pacific island of Iwo Jima looks like a large, gray pork chop. Its strategic location, midway between the U.S. B-29 airfields on the Marianas Islands and the Japanese home islands meant that it had to be seized no matter what the cost. On February 19, 1945, the invasion of Iwo Jima was launched. It became the greatest battle fought by the U.S. Marine Corps in World War II. From it came the most famous image of the war, the raising of the flag on Mount Suribachi. When it ended a month later, the Marines had suffered 20,000 casualties—almost 5,000 men killed in action. And an astonishing twenty-six Marines were awarded America's highest decoration for valor, the Medal of Honor. Best viewed with...