What was the objective of iwo jima?

Answer 1

Japan was creating an empire. They called it the "Co-Prosperity Sphere", when US declared war on Japan they began an island hopping campaign to take some of these islands because of there key locations; iwo jima is one of these islands

Answer 2

Iwo Jima was the first Japanese-held island to be taken that was considered as part of Japan. It therefore had quite a great deal of Japanese national pride at stake.

Iwo Jima was also the site of a significant airfield. If the Japanese held this base, bombing and kamikaze raids against an American fleet attempting to invade Japan would be extremely destructive. America had to prevent Japan from using that base.

America also wanted a forward base for bombers to attack Japan and Iwo Jima was close enough to the main islands to be very useful. However, it was never a primary base for American bombers. When American long-range bombers became plentiful, better airfields further from Japan were used. American planes did make good use of Iwo Jima as an emergency base. The sudden end to the war then prevented the need for an invasion of Japan, so in retrospect (with 65 years to reflect) it turns out that Iwo Jima was not worth the terrible sacrifice in taking it. At the time, though, it appeared essential to American victory.