What is often overlooked in the history of the battle for Iwo Jima is the reason why the island was invaded. The USAAF was beginning the heavy bombardment of the Japanese home islands from Tinian and other bases, and an emergency landing strip was needed for the B-29's on te round trip to Japan. The first battled damaged B-29 actually ditched in the water alongside the Navy ships during the 8th day of the battle, way before the island was taken. Later, during the end of the campaign, when the emergency airfield was operating, but a third or so of the island was still in Jap hands, some bombers that successfully made emergency landings were destroyed on the ground by Japanese mortars.
It's been conservatively estimated that the lives of over 15,000 American aircrew were saved by the capture of Iwo Jima.