Gilbert and Marshall Islands campaign
The Gilbert and Marshall Islands campaign were a series of battles fought from August 1942 through February 1944, in the Pacific theatre of World War II between the United States and Japan. They were the first steps of the drive across the Central Pacific by the United States Pacific Fleet and Marine Corps. The purpose was to establish airfields and naval bases that would allow air and naval support for upcoming operations across the Central Pacific. Operation Galvanic and Operation Kourbash were the code names for the Gilberts campaign (in modern Kiribati) that included the seizures of Tarawa and Makin, during the Battle of Tarawa on 20–23 November 1943 and the Battle of Makin on 20–24 November 1943. Operation Flintlock and Operation Catchpole were aimed at capturing Japanese bases at Kwajalein, Eniwetok, and Majuro in the Marshall Islands.
Not to be confused with Marshalls–Gilberts raids.Background[edit]
The Imperial Japanese Navy occupied the Gilbert Islands three days after the attack on Pearl Harbor. They built a seaplane base on Makin and dispersed troops along the coastlines of the northern atolls to monitor the Allied forces' movement in the South Pacific.[1] The Marshall Islands is located approximately 220 miles (350 km) northwest of the Gilbert Islands and had been occupied by the Japanese since World War I as part of the South Seas Mandate. The Japanese regarded the islands as an important outpost for their navy.[2]
Allied commanders knew that an eventual surrender of Japan would require penetration of these islands. While General Douglas MacArthur, commander of the United States Army, wanted to push towards the Philippines via New Guinea, United States Navy Admiral Chester W. Nimitz favored a drive across the Central Pacific, leapfrogging through the Gilberts, the Marshalls, the Carolines, and the Marianas, which would put American B-29 bombers within range of Tokyo.[3] In addition to forcing the Japanese to fight two fronts against the Allies (Nimitz driving from the east and MacArthur from the south), Nimitz's plan would neutralize the outer Japanese defenses, allowing American ground, naval, and air bases to be stationed there for future attacks against other occupied island groups. These outer islands included the atolls of Tarawa and Makin in the Gilberts, and Majuro, Kwajalein, and Eniwetok in the Marshalls.[4]
Gilberts[edit]
Prelude[edit]
Japanese forces occupied the Gilbert Islands on 9-10 December 1941, landing troops of the South Seas Detachment on Tarawa and Makin Islands (now Butaritari and Makin),[5] a few days after the attack on Pearl Harbor, in order to protect their southeastern flank from Allied counterattacks and isolate Australia. The islands were to become a staging post for the planned invasion of the Ellice Islands under the codename Operation FS, but their setback at the Battle of the Coral Sea delayed the plans, and their defeat at the Battle of Midway and later in the Guadalcanal campaign put a definitive end to it.
Following Carlson's Raiders' diversionary raid on Makin Island and the defeat at Guadalcanal, the Japanese command was growing aware of the vulnerability and strategic significance of the Gilbert Islands, and started adopting a defensive stance. Although Imperial leaders wanted to heavily fortify the Marianas and Palau before the Americans could get there, commanders in the outer islands were told to hold the island as long as possible.[4][3][6] Fortifications were quickly improved by the Japanese, starting in March 1943. Makin Atoll had a seaplane base built on the main island of Butaritari, while Tarawa housed barely enough room for an airfield on its main harbour island, Betio.
Battle of Tarawa[edit]
When the Americans landed, in the Battle of Tarawa fought on 20–23 November 1943, nearly 5,000 Imperial Japanese Naval Landing Forces, among them 3,000 Special Naval Landing Forces and 1,247 construction laborers, were stationed on Tarawa; the Makin Islands, in contrast, were only held by a total of 798 combat troops, including some 100 isolated Japanese aviation personnel.[7] A detachment of soldiers from Tarawa island also occupied the island of Abemama in September 1942,[8] and though initially numbering about 300, by the time the Americans invaded the island in November 1943, most of them had been evacuated back to Tarawa, leaving only 25 Special Naval Landing Forces behind to defend the island.[9]
Lieutenant Junior Grade Seizo Ishikawa, the Japanese commander in charge of defending Makin, ordered his troops to build extensive fortifications on the island. These included 8 in (203 mm) coastal defense guns, 1.5 in (38 mm) anti-tank gun positions, machine gun emplacements, rifle pits, 15 feet (4.6 m) deep tank barriers with anti-tank guns and barbed wire. These were designed to hold the island until reinforcements could arrive.
Keiji Shibazaki had 4,836 troops, including around 2,600 Special Naval Landing Forces, 1,000 Japanese construction workers and 1,200 Korean laborers. He planned to use these units to primarily defend Betio, the largest island in the atoll. Betio was the site of a crucial Japanese airfield. To protect it from capture, Keiji had 14 coastal defense guns, 50 pieces of field artillery, 100 machine gun nests, and 500 pillboxes installed, as well as a large wall built across the northern lagoon.[10]
Under heavy casualties, the U.S. Marines took the island after 3 days of fighting. Many officers questioned the significance of the invasion and heavy loss of American lives.
Aftermath[edit]
In the Gilberts, the Americans emerged victorious but were caught unprepared, suffering 2,459 dead and 2,286 wounded. Japan suffered a total of 5,085 dead and 247 captured.[11] The heavy casualties and gruesome fighting conditions for both sides convinced General Holland Smith, commanding general of the V Amphibious Corps, that Tarawa should have been bypassed, although other American admirals disagreed.[12]
The Marshalls, by contrast, were a much easier landing. The Americans used the lessons learned at Tarawa by outnumbering the enemy defenders nearly 6 to 1 with heavier firepower (including use of armor-piercing shells) after the islands took nearly a month of heavy air and naval bombardment.[6] In the Marshalls, the Americans lost 611 men, suffered 2,341 wounded, and 260 missing, while the Japanese lost over 11,000 men and had 358 captured.[11]
After the Gilberts and Marshalls were taken, the Allies built naval bases, fortifications, and airfields on the islands to prepare for an assault on the Marianas.[2] The Japanese defeat forced military leaders to draw back to a new defensive perimeter, the Absolute National Defense Zone, which included the Marianas and Palau. These islands were heavily fortified for an upcoming assault because if captured they would put American heavy bombers within range of Tokyo.[3]