The 18th Infantry Brigade of the Australian 7th Division and elements of the Australian 14th Brigade, under the command of Cyril Clowes, were in charge of the defense of the base at Milne Bay. The attacking force was the elite Japanese Special Naval Landing Forces commanded by Minoro Yano. The Battle of Milne Bay began at 11:30 hours on August 25, when the the Japanese landed 1,150 troops and two Type 95 Ha-Go tanks, at Ahioma on the northern shore of Milne Bay, ten miles east of their intended landing area.

The tiny island of Gavutu was defended by 536 Japanese naval personnel from the Yokohama Air Group and 3rd Kure Special Naval Landing Force and Korean and Japanese civilian technicians and laborers from the 14th Construction Unit. The Gavutu and Tanambogo islands were basically mounds of coral, both about 140 ft high, and connected to each other by a 500 yard-long causeway. The hills on Gavutu and Tanambogo were called Hills 148 and 121 respectively by the Americans because of their height in feet. The Japanese on both islets were well entrenched in caves and pillboxes which had been built on and in the two hills. Also, the two islets were mutually supportive since each was in machine gun range of the other.

The Battle of Gavutu began at 12:00 hours on August 7, 1942. At that time this small coral island was assaulted by the US Marine 1st Parachute Battalion which was composed of 397 men. The attack on Gavutu was initiated at noon since there were not enough aircraft to provide air cover for the Guadalcanal, Tulagi, and Gavutu landings at the same time. As the American naval bombardment had damaged the seaplane ramp, the Marines were forced to land in a more exposed location on a nearby small beach and dock at 9°6’53.30 S 160°11’19.20 E / 9.114806°S 160.188667°E / -9.114806; 160.188667 (Gavutu Landing). As soon as they set foot on the beach Japanese machine guns opened fire on them inflicting heavy casualties, killing or wounding one in ten of the landing Marines as they scrambled inland in an attempt to get out of the crossfire coming from the two islets.

Nevertheless, Marines were tenacious fighters and managed to deploy two machine guns to provide suppressing fire on Gavutu’s caves. This allowed more Marines to push inland from the landing area. On Tanambogo, the Marines became scattered and were quickly pinned down. Captain George Stallings, the battalion operations officer, directed Marines to begin suppressive fire with machine guns and mortars on the Japanese machine gun emplacements. US dive bombers were called in and dropped several bombs on Tanambogo, diminishing some of the volume of fire from that location.

At 14:00 hours on August 7, Marines reached and climbed Hill 148 on Gavutu. Then, the Marines began clearing the Japanese fighting positions on the hill with explosive charges, grenades, and hand-to-hand combat. From the top of the hill 148 on Gavutu islet, the Marines were also able to put increased suppressive fire on Tanambogo. The Marine battalion commander on Gavutu radioed General Rupertus with a request for reinforcements before attempting to assault Tanambogo.

During the night, as the Japanese launched isolated attacks on the marines on Gavutu under the concealment of heavy thunderstorms, the American comander, Alexander Vandegrift, sent reinforcements to assist with the assault on Tanambogo. The 3rd Battalion 2nd Marines (3/2), still embarked on ships off Guadalcanal, was notified to prepare to assault Tanambogo on August 8. The 3rd Battalion began landing on Gavutu at 10:00 on August 8 and assisted in destroying the remaining Japanese defenses on that islet, which was completed by 12:00.

With the Marines 1st Parachute Battalion on Gavutu providing covering fire for the attack, the 3rd Battalion began the assault on Tanambogo at 16:15 hours on August 8, both by landing craft and across the causeway. They began making headway with assistance from two marine Stuart light tanks against the Japanese defenses. One of the tanks which became stuck on a stump and isolated from its infantry support was surrounded by a "frenzied mob" of about 50 Japanese airmen. The Japanese set fire to the tank, killing two of its crew and severely beat the other two crewmembers before most of them were killed by Marine rifle fire.

Throughout the remainder of August 8, the Marines methodically blew up the caves explosives, destroying most of them by 21:00 hours. The few surviving Japanese conducted isolated attacks throughout the night, with hand to hand engagements occurring. By noon on August 9, all Japanese resistance on Tanambogo had been crushed. In the battle for Gavutu and Tanambogo, 476 Japanese defenders and 70 U.S. Marines or naval personnel were killed in action. Of the 20 Japanese prisoners taken during the battle, most were not actually Japanese combatants but Korean laborers belonging to the Japanese construction unit.

The Battle of Tulagi was initiated at 08:00 hours on August 7, 1942, when two battalions of U.S. Marines, which included the 1st Raider Battalion under Lieutenant Colonel Merritt A. Edson, and the 2nd Battalion, 5th Marines, landed on the western shore of Tulagi about halfway between the two ends of the oblong-shaped island. The landings were not easy for the Marines as Japanese resistance was stiff and ferocious from the very beginning. Nevertheless, the Marines fought tenaciously and relentlessly, and by the end of the day of August 9, they had crushed the last pockets of resistance. The Japanese had fought and died almost to the last man. The most vicious and brutal part of the Battle of Tulagi was the assault on Hill 280, which took place on August 8. After pounding the Japanese positions on top of Hill 280 with mortar fire, the Americans assaulted the last positions, using improvised explosive charges to kill the Japanese defenders.

On September 15, 1944, the US forces had just landed on Peleliu, initiating the Palau islands campaign. Angaur was a three-mile long volcanic island defended by a Japanese force composed of 1,400 troops, under the overall command of Palau Sector Group commander, Lieutenant General Sadae Inoue. Like all the rest of the Japanese-held Pacific islands, it was well defended by a system of pillboxes, casemates, holes and tunnels.

Preceded by heavy bombardment carried out by the battleship USS Tennessee, cruisers, and Dauntless dive bombers from USS Wasp, the Battle of Angaur began at 08:15 hours on September 17, 1944, when the U.S. 81st Infantry Division commanded by Major General Paul J. Mueller landed on the northeast and southeast coasts. Mines and congestion on the beach initially gave more trouble than Japanese counter-attacks. But resistance stiffened as the Americans advanced on "the Bowl", a hill near Lake Salome in the northwest of the island where the Japanese planned to make their last stand. From September 20 the 322nd battalion repeatedly attacked the Bowl, but the 750 defenders repulsed them with artillery, mortars and machine guns. Gradually hunger, thirst, and American shellfire and bombing took their toll on the Japanese, and by September 25 the Americans had penetrated the Bowl. Rather than fight for possession of the caves, they used bulldozers to seal the entrances. By September 30, the last pockets of resistance had been snuffed out by the brave American soldiers and island had finally been secured.

Between June and August, 1944, the US forces had recaptured the Japanese-held islands of Saipan, Guam, and Tinian in the Mariana islands, Central Pacific, bringing the war closer to Japan as American bombers were now able to strike at the Japanese main islands. Before launching an assault on the Philippines, General Douglas MacArthur and Admiral Chester Nimitz had agreed that they had to attack the island of Peleliu first in order to gain another foothold from which to continue the Pacific Campaign. The 1st, 5th, and 7th Marine Divisions were assigned to begin the initial assualt on Peleliu. One of the objectives of the US Marines was to capture the airstrip of the island.