After the Battle of Midway in the summer of 1942, the United States launched a counter-offensive strike known as "island-hopping," establishing a line of overlapping island bases. As each Japanese-held island fell, U.S. forces quickly constructed airfields and small bases, then moved on to surrounding islands, one after another, until Japan came within range of American bombers. The volcanic island of Iwo Jima was a crucial location for the island-hopping campaign to succeed. The island's...