All U.S. services, including the Coast Guard, participated in Operation Forager in 1944, designed to capture Central Pacific islands of the Mariana and Palau in Micronesia from the Japanese during World War II.
Seizing these islands would put the B-29 long-range bomber within striking distance of Japan. A number of island battles took place, but the main battles were on the islands of Saipan, Tinian and Guam and Peleliu.
The Battle of Saipan lasted from June 15 to July 9, 1944. The 2nd Marine Division, 4th Marine Division and the Army's 27th Infantry Division participated. The Navy's 5th Fleet also joined in the battle, providing transport, bombing and close air support.
Fighting was described as brutal, but in the end, U.S. forces defeated the Japanese 43rd Infantry Division.
The Battle of Tinian lasted from July 24 to Aug. 1, 1944. The 4th Marine Division provided the bulk of the landing force. They were supported by naval bombardment. Since Tinian is just a few miles from Saipan, Marines on Saipan fired artillery into Tinian. The Marines all but eliminated the 8,000-strong Japanese defenders.
The Battle of Guam lasted from July 21 to Aug. 10, 1944. Marines from the 3rd Marine Amphibious Corps and the Army's 77th Infantry Division, supported by naval landing craft and gunfire, provided the bulk of the force.
The Battle of Peleliu lasted from Sept. 15 to Nov. 27, 1944. U.S. forces consisted at first of the 1st Marine Division. Later, soldiers of the 81st Infantry Division joined them. Despite heavy U.S. casualties, the Japanese 14th Infantry Division was nearly wiped out.
There is significant debate about Peleliu, but the consensus is there was little strategic value in taking the island, said Mike Westermeier, a historian in the Marine Corps History Division. It was never used as an airfield or a major staging area for subsequent operations.
Some argue that the Marines gained valuable experience fighting against the types of fortifications they would encounter later on Okinawa, but it still seems difficult to justify a battle that incurred such high casualties for little strategic gain, he noted.
Regarding joint operations during Operation Forager, Westermeier said the 5th Amphibious Corps, which was the higher headquarters for the Marine divisions on Tarawa and Saipan, worked extremely well with the Navy. The Marine landing force was able to get two days of preliminary bombardment on the beaches as they requested, although the bombardment proved to be somewhat ineffective against the Japanese defenses.
Naval aviation worked very well with Marine air liaison teams to provide close air support to the Marines ashore. Army 24th Corps artillery provided fire support for Marines and soldiers using its 155 mm howitzers against Japanese caves and bunkers, he said.
"Sadly, interservice rivalry between Marine Corps Lt. Gen. Holland M. Smith, 5th AC commander, and Army Maj. Gen. Ralph C. Smith, 77th Infantry Division commander, led to controversy when Lt. Gen. Smith relieved — and some would argue without cause — Maj. Gen. Smith during the battle," he said.
"This led to a deterioration in Army-Marine cooperation, and the fallout was felt in operations through the end of the war, as many Army commanders refused to serve under Lt. Gen. Smith," Westermeier said. Consequently, he added, Smith was sidelined and Navy Adm. Chester Nimitz, commander in chief, Pacific Ocean Areas, chose Army Lt. Gen. Simon Bolivar Buckner Jr. to command the 10th Army for the Okinawa operation in 1945.