Battle of the Bismarck Sea
The Battle of the Bismarck Sea (2–4 March 1943) took place in the South West Pacific Area (SWPA) during World War II when aircraft of the U.S. Fifth Air Force and the Royal Australian Air Force (RAAF) attacked a Japanese convoy carrying troops to Lae, New Guinea. Most of the Japanese task force was destroyed, and Japanese troop losses were heavy.
The Japanese convoy was a result of a Japanese Imperial General Headquarters decision in December 1942 to reinforce their position in the South West Pacific. A plan was devised to move some 6,900 troops from Rabaul directly to Lae. The plan was understood to be risky, because Allied air power in the area was strong, but it was decided to proceed because otherwise the troops would have to be landed a considerable distance away and march through inhospitable swamp, mountain and jungle terrain without roads before reaching their destination. On 28 February 1943, the convoy – comprising eight destroyers and eight troop transports with an escort of approximately 100 fighter aircraft – set out from Simpson Harbour in Rabaul.
The Allies had detected preparations for the convoy, and naval codebreakers in Melbourne (FRUMEL) and Washington, D.C., had decrypted and translated messages indicating the convoy's intended destination and date of arrival. The Allied Air Forces had developed new techniques, such as skip bombing, that they hoped would improve the chances of successful air attack on ships. They detected and shadowed the convoy, which came under sustained air attack on 2–3 March 1943. Follow-up attacks by PT boats and aircraft were made on 4 March on life boats and rafts. All eight transports and four of the escorting destroyers were sunk. Of 6,900 troops who were badly needed in New Guinea, only about 1,200 made it to Lae. Another 2,700 were rescued by destroyers and submarines and returned to Rabaul. The Japanese made no further attempts to reinforce Lae by ship, greatly hindering their ultimately unsuccessful efforts to stop Allied offensives in New Guinea.
Background[edit]
Allied offensives[edit]
Six months after Imperial Japan attacked Pearl Harbor in December 1941, the United States won a strategic victory at the Battle of Midway in June 1942. Seizing the strategic initiative, the United States and its Allies landed on Guadalcanal in the southern Solomon Islands in August 1942, beginning the Solomon Islands Campaign. The battle for Guadalcanal ended in victory for the Allies with the withdrawal of Japanese forces from the island in early February 1943. At the same time, Australian and American forces in New Guinea repelled the Japanese land offensive along the Kokoda Track. Going on the offensive, the Allied forces captured Buna–Gona, destroying Japanese forces in that area.[3][4]
The ultimate goal of the Allied counter-offensives in New Guinea and the Solomons was to capture the main Japanese base at Rabaul on New Britain, later codified as Operation Cartwheel, and clear the way for the eventual reconquest of the Philippines. Recognising the threat, the Japanese continued to send land, naval, and aerial reinforcements to the area in an attempt to check the Allied advances.[5]
Japanese plans[edit]
Reviewing the progress of the Battle of Guadalcanal and the Battle of Buna–Gona in December 1942, the Japanese faced the prospect that neither could be held. Accordingly, Imperial General Headquarters decided to take steps to strengthen the Japanese position in the South West Pacific by sending Lieutenant General Jusei Aoki's 20th Division from Korea to Guadalcanal and Lieutenant General Heisuke Abe's 41st Division from China to Rabaul.[6] Lieutenant General Hitoshi Imamura, the commander of the Japanese Eighth Area Army at Rabaul, ordered Lieutenant General Hatazō Adachi's XVIII Army to secure Madang, Wewak and Tuluvu in New Guinea. On 29 December, Adachi ordered the 102nd Infantry Regiment and other units under the command of Major General Tōru Okabe, the commander of the infantry group of the 51st Division, to move from Rabaul to Lae and advance inland to capture Wau.[7] After deciding to evacuate Guadalcanal on 4 January,[8] the Japanese switched priorities from the Solomon Islands to New Guinea, and opted to send the 20th and 41st Divisions to Wewak.[6]
Game theory[edit]
In 1954, O. G. Haywood Jr., wrote an article in the Journal of the Operations Research Society of America in which game theory was used to model the decision-making in the battle.[78] Since then, the name of the battle has been applied to this particular type of two-person zero-sum game.[79]