Iwo Jima was a critical point on the flight path of US bombers from their Saipan bases to their Japanese targets. The island would be a refuge for malfunctioning or damaged bombers coming or going. An obvious target for a US amphibious assault, the Japanese had reinforced the garrison & dug miles of tunnels the length & breadth of the isl&. Their goal was to inflict maximum casualties on the Americans to force them to reconsider the seemingly inevitable invasion of Japan. The resulting.. .