The Japanese continued to have early-warning radar from Rota island, which was never invaded, and Iwo Jima's captured air field was barely used. Pratt stating that the island was useless to the Army as a staging base, and useless to the Navy as a fleet base. The action was controversial, with retired Chief of Naval Operations William V. Overwhelming American superiority in numbers and arms, air supremacy, the impossibility of Japanese retreat or reinforcement, and sparse food and supplies for the Japanese, permitted no plausible circumstance in which the Japanese could have won the battle.

Despite the fighting and severe casualties on both sides, the American victory was assured from the start. Most of the remainder were killed in action, but it has been estimated that as many as 3,000 continued to resist within the various cave systems for many days afterwards until they eventually succumbed to their injuries or surrendered weeks later. Of the 21,000 Japanese soldiers on Iwo Jima at the beginning of the battle, only 216 were taken prisoner, some of whom were captured only because they had been knocked unconscious or otherwise disabled. The Japanese combat deaths numbered three times the number of American deaths, but uniquely among Pacific War Marine battles, the American total casualties (dead and wounded) exceeded those of the Japanese. The five-week battle saw some of the fiercest and bloodiest fighting of the Pacific War. Navy and Marine Corps aviators throughout the battle.

The American ground forces were supported by extensive naval artillery and had complete air supremacy provided by U.S. The Japanese Army positions on the island were heavily fortified, with a dense network of bunkers, hidden artillery positions, and 18 km (11 mi) of tunnels.

The American invasion, designated Operation Detachment, had the purpose of capturing the island with its two airfields: South Field and Central Field. The Battle of Iwo Jima (19 February – 26 March 1945) was a major battle in which the United States Marine Corps (USMC) and United States Navy (USN) landed on and eventually captured the island of Iwo Jima from the Imperial Japanese Army (IJA) during World War II.

Weather underground radar map