Initially, both Spruance and Nimitz thought that it would not take much effort to capture such a small island, but after looking at aerial photographs taken by the aerial reconnaissance of Iwo Jima, they realized that there was a very high probability of an unusual defense system on this island, and after carefully studying the aerial photos, Lieutenant General Smith said that it would be the most difficult island to capture, and estimated 20,000 casualties. Pen? Interesting? Pavilion wWw. ｂiquge。 ｉｎfo

On January 28, the 24th year of the Taichu Dynasty, the commander of the 21st Air Force of the Army Air Corps, which was responsible for organizing the strategic bombing of the Japanese mainland, was in charge of organizing the strategic bombing of the Japanese mainland. When Rear Admiral Li May came to consult with the air force on how to support the Iwo Jima landing operation, Spruance asked him how much Iwo Jima was worth to the war. Li May immediately affirmed that without Iwo Jima, it would not be possible to effectively carry out strategic bombing of the Japanese mainland. Spruance was relieved and determined to capture Iwo Jima at great cost.

On February 2, the twenty-fourth year of the first lunar calendar, Nimitz came to Ulisi to inspect the preparations for the battle on Iwo Jima. Spruance proposed that in order to prevent possible Japanese reinforcements to Iwo Jima, carrier-based aviation must first be used to suppress the airfields in the Kanto region on the Japanese mainland, and Nimitz agreed to this plan. Nimitz then traveled to Saipan to observe the combat exercises conducted by three Marine Divisions of the Fifth Amphibious Corps, which were to carry out landing operations on Iwo Jima.

On February 10, the 24th year of the beginning of the first century, Spruance led an aircraft carrier formation consisting of 12 aircraft carriers, 8 battleships, 15 cruisers, and 77 destroyers, with the heavy cruiser USS Indianapolis as the flagship, and Mitchell, commander of the 58th Task Force, with the aircraft carrier "Bunker Hill" as the flagship, sailed out of Ulisi, passed east of the Mariana Islands and Ogasawara Islands, and went straight to the Japanese mainland. Spruance planned to arrive off the coast of Japan on the 16th, and on the 16th and 17th, he would carry out a suppressive air raid on the airfield in the Kanto region of the Japanese mainland, and then move south to participate in the Iwo Jima operation. He was particularly worried about the threat of Japanese kamikazes, so there were only 30 bombers and torpedo planes on each aircraft carrier, and the rest were all fighters. In order to minimize the possibility of being discovered by the Japanese troops, a number of submarines were dispatched to serve as reconnaissance and search in front of the formation channel, while the shore-based air force on Saipan used B-24 and B-29 to patrol and guard the sea area through which the formation passed. The formation itself also used a number of destroyers to form a search screen in front of the formation, and at the same time used carrier-based aircraft to conduct 24-hour uninterrupted antisubmarine vigilance. It was precisely because of the above-mentioned strict precautions and the cover of bad weather that the US aircraft carrier group reached the sea area 125 nautical miles southeast of Tokyo at dawn on the 16th, only 60 nautical miles from the nearest coast of the Japanese mainland, and was still not discovered by the Japanese army.

On 16 February, the 24th year of the Taichu Dynasty, the US aircraft carrier squadron flew more than 1,000 sorties of carrier-based aircraft, divided into several attack waves, and attacked various airfields in Tokyo Bay.

On 17 February, the 24th year of the beginning of the Taichu period, the US military flew more than 500 sorties of two attack wave carrier-based planes to bomb airfields, aircraft factories, anchored ships, and other targets in the Kanto region. In two days, the US military shot down 332 Japanese planes and destroyed 177 Japanese planes on the ground in air battles, causing some damage to some airfields and aircraft factories. In the afternoon of the same day, the US aircraft carrier group left the coast of Japan and headed south to participate in the Iwo Jima operation.

On February 14, the twenty-fourth year of the Ethernet, William. Rear Admiral Brandi led a fire support formation consisting of 6 battleships, 12 escort carriers, 5 cruisers, and 16 destroyers from Saipan to Iwo Jima.

On February 15, the 24th year of the first century, U.S. Secretary of the Navy Forrestal, accompanied by Nimitz, arrived on Saipan Island to listen to a report on the Battle of Iwo Jima and inspect the preparations for the battle. Turner, commander of the landing formation, known as the "alligator," who had just recovered from a serious illness, reported that he had planned to prepare for 10 days of artillery fire on Iwo Jima, because the warships could not carry the ammunition for the 10-day shelling and could only carry out three days of shelling, but Turner said that three days of artillery bombardment of a small island with an area of only 20 square kilometers was sufficient, and the defense that could not be destroyed by artillery fire would be completed by the landing force.

In the early morning of February 16, the 24th year of the first century, Brandy's fire support formation arrived in the waters off Iwo Jima and began to carry out advance fire preparations. All battleships, cruisers were divided into lots, and the identified targets were destroyed one by one. To ensure the accuracy of the shelling, several battleships even conducted direct aimed fire at the target at a distance of only 3000 meters from the shore. However, due to the bad weather and the smoke of gunfire on the island, only 17 of the 750 targets scheduled were destroyed, and the shelling effect was far from ideal. The Japanese counterattacked with only some small and medium-caliber guns, damaging one battleship and one cruiser, and the large-caliber guns did not fire a single shot out of concealment considerations.

On February 17, the 24th year of the beginning of the Taichu Dynasty, under the cover of 12 landing gunboats, the US underwater demolition team probed the channel of the beach reef and cleared the underwater mines and obstacles. The U.S. military was shocked that the Japanese troops on the island still had such heavy firepower, and immediately bombarded these newly exposed targets.

During the three days from the 16th to the 18th, in addition to the naval artillery firepower, the carrier-based aircraft escorting the aircraft carrier also made all-out attacks, and some carried out air cover; some carry out anti-submarine vigilance; Some observations are corrected to pop up; Some threw incendiary bombs at the Japanese positions, burning the camouflage of the Japanese positions and exposing them so that the naval guns could destroy them. And Saipan's bombers also frequently came to help in the war, bombing Iwo Jima. During these three days, Iwo Jima was almost completely overwhelmed by the smoke of American fire, and the Japanese troops had to huddle in the tunnels and could not move. According to statistics, the US military consumed more than 24,000 tons of artillery shells and bombs before landing, and the average of 1,200 tons per square kilometer on Iwo Jima was borne by the Japanese army.

At 6 a.m. on February 19, the 24th year of the first year, the landing group led by Turner arrived in the waters of Iwo Jima, and the aircraft carrier group commanded by Spruance and Mitchell also arrived in the northwest waters of Iwo Jima.

At 6:40 p.m., seven battleships, four heavy cruisers, and 13 destroyers of the US naval artillery support formation began direct fire preparations, and the aircraft carrier group took part in the aviation fire preparations against Iwo Jima while taking on air cover. Although the time for this firepower preparation was short, the effect was relatively satisfactory because the weather was sunny and the target was clearly visible.

The three divisions of the landing force of the Marine Corps, with the fourth and fifth divisions of the Marine Division as the first echelon and the third Marine Division as the reserve, completed the transfer of eight battalions of the first batch of the landing force while preparing for direct firepower.

The landing beachhead is on the east beach of Iwo Jima, extending northeast along the coast from the foot of Mt. Oriba, with a total length of 3,150 meters, and is divided into a landing beachhead every 450 meters from south to north, with the code names of Green One, Red One, Red Two , Yellow One , Yellow Two , Blue One and Blue Two respectively. The 5th Marine Division landed at three beachheads at the southern end and crossed the narrowest part of the island to isolate or capture Mount Oribo in the south of the island, while the 4th Marine Division landed on four beachheads in the north and attacked Airfield 1.

At 8:30 a.m., the first wave of 68 tracked landing vehicles left the starting point and stormed the beachhead. At 8:59 a.m., the ship's artillery fire began to extend its firing. At nine o'clock, the troops began to land on time, and the beginning was very smooth, the resistance of the Japanese troops was very weak, only sporadic fire from mortars and light weapons, and the biggest obstacle encountered by the US troops was the volcanic ash on the beach, because the beach was all made of volcanic ash, the soil was soft and abnormal, and the tracked landing vehicles were all trapped in the volcanic ash, and it was difficult to advance, and the landing craft behind them sailed ashore one after another, but they were blocked by these immobile tracked landing vehicles, and they could not rush to the beach and land at all, and the landing troops on the boats had to wade ashore. Seeing that the Japanese had only sporadic small arms fire, Turner even thought that with this development, it would only take five days to occupy the entire island. Spruance, who was in charge of fire support, even sent a telegram to Admiral Nimitz*: "Maybe I'm crazy, did the Japanese give up resistance." The resistance we encounter today is not even stronger than the fire of the Navajo attacking the caravan, is it the April Fool's Day of the Japanese today? Nimitz, on the other hand, was clearly hopeless, and his reply was very succinct: "Please cut out all the words that may have been my madness." ”

Sure enough, the good times did not last long, and the landed American troops advanced more than 200 meters, and the Japanese troops waited for the American artillery fire to begin to extend, so Kuribayashi ordered to enter the position through the tunnel, and according to the data that had been calculated in advance, the Japanese artillery fire accurately covered the landing beachhead, and for a time, the American troops were completely suppressed on the beachhead, suffering heavy casualties, and the advance was blocked.

Because the 5th Marine Division was shelled about 20 minutes later than the 4th Marine Division, and the artillery fire was relatively weaker than that of the 4th Marine Division, the 1st Battalion of the 28th Regiment, which was in the vanguard, was able to take advantage of this opportunity to cross the narrowest part of the island and cut off the Japanese forces in the other areas, while the 2nd Battalion then launched an attack on Oribayama. The 4th Marine Division was almost unable to move an inch under heavy Japanese artillery fire. At such a critical moment, the U.S. naval artillery fire gave the landing force extremely powerful support, and in this landing, each battalion of the U.S. landing force was equipped with a naval artillery fire control group, which was able to summon the support of naval artillery fire in a timely manner, and the school firing aircraft in the air also played a huge role in accurately determining the position of the Japanese artillery fire to guide the naval guns to eliminate it. The US landing force advanced with difficulty, and the US military consumed a total of 38,550 rounds of naval artillery shells of more than 127 mm caliber throughout the day, and the fire support was unprecedented.

At 9:30 a.m., the US tanks came ashore and immediately guided and covered the attack of the landing force. Most of the tanks, which were supposed to play a huge role, fell into the ash and could not move, and a few of them also faltered, and soon became the target of the Japanese anti-tank guns and were destroyed one by one. The U.S. military could only rely on soldiers to advance with explosives packs and flamethrowers, one step at a time, and each step had to pay a heavy price.