January-May 1945, Cutting the Empire in Two
Overview:
According to the postwar United States Strategic Bombing survey, of the 28,500,000 barrels of oil its leaders expected to import from the Dutch East Indies in 1944, it imported only 4,975,000 barrels. In 1945 its imports were even further restricted to the few thousand barrels brought in during the months of January and February by a few single tankers that succeeded in passing through the blockade. After the battles of early 1945, when Japan lost the Philippines and Okinawa, United States forces sat astride its vital oil life line. Strategically the war was already won.
January 1945 saw the bloodbath of tankers and merchant vessels in the South China Sea region bounded by Formosa, Luzon, Hainan, Borneo, and Malaysia, draw to a close. To solidify these gains the Allies targeted Japanese coastal shipping. The U.S. Third Fleet dispatched a task force into the South China Sea to raid Japanese shipping lanes, target IJN vessels in the region and support General Douglas MacArthur's forthcoming invasion of the Philippine island of Luzon. The Fast Carrier Task Force (Task Force 38), commanded by Vice-Admiral John McCain was the first sizeable Allied element to operate within the South China Sea since the beginning of the war. The task force sunk 60 merchant vessels during a series air raids on Japanese targets in French Indochina, mainland China, Formosa and Luzon between 10 and 20 Jan 1945. These U.S. attacks effectively ended the ability of Japanese merchant fleet to connect the Home Islands to its empire in South East Asia.
By the end May 1945, coastal shipping, Japan's final lifeline to South East Asia was completely interdicted. When US forces regained control over strategic portions of the Philippines, the oil-rich Dutch East Indies were cut off. Japan went so far as to create oil carrying submarines to attempt move oil back to the Home Islands. The Allies compounded the loss of these shipping lanes with the invasion Japanese occupied Borneo. The Allies launched Operation Oboe, and seized oil production sites from the Japanese empire. By the end of June 1945, the Allies seized facilities in Lutong, Tarakan, and Balikpapan. The Allies sunk a mere 16 vessels south of the Japanese Home Islands between June and August 1945. With the Japanese empire effectively split in two, Allied planners would focus their efforts on isolating the Home Islands from Korea and mainland China.
With Japan's oil remaining oil supplies severly rationed, the US Navy's next target was cutting off the coastal traffic that moved supplies in between the major Japanese islands. Previously this traffic had proved to be difficult to interdict because of shallow waters and enemy minefields. Turning the enemy's tactics against them, the US Navy coordinated with the US Army Air Force to mine the the coastal waters of Japan. US Navy submarines and USAAF B-29 Superfortresses would both work in concert to achieve this effect.
The mission was initiated at the insistence of Admiral Chester Nimitz who wanted his naval operations augmented by an extensive mining of Japan itself conducted by the air force. While General Henry H. Arnold felt this was strictly a naval priority, he assigned General Curtis LeMay to carry it out. A B-29 dropping sea mines over Japanese home waters LeMay assigned one group of about 160 aircraft of the 313th Bombardment Wing to the task, with orders to plant 2,000 mines in April 1945. The mining runs were made by individual B-29 Superfortresses at night at moderately low altitudes. The individual B29's radar provided mine release information.
Working together on the remote Pacific island of Tinian, Army Air Force and Navy personnel turned a mission that began as an inter-service rivalry into one of the best examples of inter-service cooperation of the Pacific War. The main objectives of Operation Starvation were to prevent the importation of raw materials and food into Japan, prevent the supply and movement of military forces, and disrupt shipping in the Inland Sea. Forty-six missions were directed against Japanese home waters with the intention of blockading the Shimonoseki Straits, through which 80 percent of the Japanese merchant fleet passed; blockading the industrial and commercial ports of Tokyo and Nagoya in the Inland Sea; and interdicting shipping between Korea and Japan by mining Korean ports and ports on the northern coast of Japan
January to March 1945:
Expanded Legend:
- The territorial waters around the island Okinawa are swept of Japanese shipping in support of U.S. invasion. The heavy attacks by land-based aircraft, carrier-based aircraft, and submarines take a heavy toll of Japanese merchant shipping. U.S. submarines and naval aircraft sunk 25 vessels in March 1945 in preparation of the invasion.
- U.S. forces forces interdict coastal traffic along mainland China, sinking 77 merchant vessels as well as mining the Yellow River inland and sinking five ships far upriver. The strangling of Japanese supply lines was a preview of what was to come in the next four months off the shores of Japanese occupied Korea. U.S. carrier based aircraft sunk five merchant vessels in the port of Hong Kong on 16 Jan. Later, they sunk nine on 21 Jan 1945 off the southern coast of Formosa during the final sortie of the South China Sea Raid also known as Operation Gratitude.
- Aided by intelligence from Free French operatives, U.S. carrier-based aircraft destroyed 32 merchant vessels in the port of Saigon and off the coast of Indochina on 12 Jan 1945. These strikes, part of Operation Gratitude sunk over 140,000 tons of shipping and constituted the largest single day loss of Japanese merchant shipping since the Allied bombing of Truk. U.S. forces destroyed 19 more between February and March 1945, nine of those were sunk by submarines.
April to May 1945
Expanded Legend:
- In a foretaste of things to come, carrier-based aircraft sink 97 merchant vessels in littoral waters of the Japanese Home Islands during a series of raids during between January and May 1945. Operation Starvation begins in April and accelerates by the end of May.
- U.S. aircraft sink nine Japanese vessels in Chinese coastal waters, June and May 1945. These vessels were the last to be sunk in these waters by Allied forces.
- British and American forces sunk nine ships in the Gulf of Thailand and off the coast of French Indochina.
- British and American forces sunk 11 merchant vessels in advance of Operation Oboe. These sinkings, coupled with the invasion of Borneo constituted, the end of Japanese shipping out the Java Sea.
