Of all the amphibious landings of the Pacific War, Iwo Jima is the only battle where total American casualties exceeded Japanese casualties, despite total naval and air supremacy and an invasion force of over 110,000 men. This episode explores Operation Detachment, the 36-day fight for eight square miles of volcanic rock sitting in the B-29 flight path from the Marianas, and asks the uncomfortable question of whether the island needed to be taken at all.

Lieutenant General Tadamichi Kuribayashi, cut off with no navy and no air support, forbade banzai charges, abandoned the beaches, and dug an 11-mile tunnel network with bunkers up to 90 feet underground that were invisible to aerial reconnaissance. American planners predicted the island would fall in under a week, and the Navy granted only three rain-hampered days of bombardment instead of  ...