On 19 February 1945, the 3rd, 4th, and 5th US Marine Divisions of General Holland “Howlin’ Mad” Smith’s Task Force 56 landed on the island of Iwo Jima in the Bonin’s island chain south of Japan. They were to secure Iwo Jima’s three airfields. Because the island was about halfway between the Japanese Home Islands and the B-29 airfields in the Mariannas, Iwo Jima was planned to be used for an emergency landing field, though it was rarely used as such. Nonetheless Iwo Jima was a perfect staging area for the invasion of mainland Japan, scheduled for the upcoming autumn. For the next five weeks, 70,000 Marines and Navy personnel fought 22,000 Japanese defenders under Lieut General Tadamishi Kurabayashi for control of Iwo Jima.
Kurabayashi copied the tactics of ambush and interlocking fields of fire from impenetrable pillboxes that worked so well for the Japanese on Peleliu five months before. But unlike Peleliu, the Japanese had a further advantage: the volcanic rock of Iwo Jima was much easier to tunnel through. Kurabayashi’s troops spent almost a year digging in and connecting every pillbox, artillery position, and mortar, machine gun and sniper pit by tunnel. Furthermore, the entire southern portion of the island was dominated by the dormant volcano Mt Suribachi from which Japanese spotters could observe every inch of the island. Virtually the entire Japanese defense was underground and the three day American pre-invasion bombardment was especially ineffective.
The Marine’s first waves landed unopposed and subsequent patrols failed to find the defenders. Many thought the bombardment killed them all. They could not have been more wrong.
The Japanese only opened fire when the second wave crammed itself onto the beach, just as the assault battalions began to move off. The two waves of Marines crowded on the beach took enormous casualties from hidden Japanese positions.
Kurabayashi forbade wasteful banzai charges, but the Japanese took full advantage of the mobility afforded by the extensive tunnel system. Thousands of Marines were killed or wounded from “cleared” Japanese positions that were suddenly reoccupied after the Americans moved on.
After a grueling four day fight for the southern part of the island, the Marines captured Mount Suribachi on 23 February 1945. The event was immortalized by Joe Rosenthal’s famous photo of the flag raising on the summit of the volcano. (The famous picture was actually of the second flag raised on the Mt Suribachi. The first was about an hour before but of a much smaller flag.)
Unfortunately, the hardest fights for the island were still to come. Kurabayashi’s main defensive line was further north protecting the second and third airfields on the island. The Marines were forced to clear every square foot of the island.
The only tactic that was effective against the dug in Japanese was an armored frontal assault. The Marines lead with tanks, especially the Sherman “Zippo” flamethrower tank, which forced the Japanese to attack — they had no way to stop the tanks short of physically assaulting and overrunning them. The dismounted Marines would fight off the now exposed Japanese, and then clear the Japanese positions with tank main gun rounds, satchel charges, and flamethrowers. Once the Japanese were cleared or dead, a bulldozer then sealed the inevitable connecting tunnel. The entire operation was usually under fire from supporting Japanese positions and artillery. The Marines did this until the last organized Japanese resistance ended. That occurred when the remaining defenders, out of food, water and ammunition, launched a final banzai charge led by Lieut General Kurabayashi himself (in defiance of his own orders) on 25 March 1945.
The island was declared secure, and the US Army’s 147th Infantry Regiment took over from the Marines. The 147th was an Ohio National Guard unit from Columbus Ohio, lost from the 37th Infantry Division when that division “went triangle” (Four to three regiments per division) in 1942. Starting on Guadalcanal, the 147th spent the rest of the war cleaning up after the Marines, and Iwo Jima was no different. About 1500 Japanese were still living in the tunnels and fighting on the desolate island after the Marines departed. The last two Japanese defenders didn’t surrender until 1949.
The Battle for Iwo Jima was the bloodiest and most bitterly contested amphibious operation of the Second World War. The Americans suffered 30,000 casualties including 7,000 killed in action. All but 200 of the 22,000 Japanese fought to the death. Of the 82 Congressional Medals of Honor awarded to Marines in the entire War in the Pacific, 27 were awarded for actions on the small island of Iwo Jima. Admiral Nimitz said of the Marines who fought there:
“Uncommon valor was a common virtue”.