Early Japanese conquests

In the opening months of the Pacific War, Japanese forces struck Allied bases throughout the western Pacific and Southeast Asia as part of the so-called Southern Operation. By late spring 1942, with the surrender of Allied strongholds in Singapore, Hong Kong, the Philippines, and the Dutch East Indies, an estimated 140,000 Allied prisoners of war had fallen into Japanese hands. In addition, approximately 130,000 civilians—including some 40,000 children—were captured by the Japanese. While civilians were generally treated better than military prisoners, conditions in Japanese captivity were almost universally deplorable. More than 11 percent of civilian internees and 27 percent of Allied POWs died or were killed while in Japanese custody; by contrast, the death rate for Allied POWs in German camps was around 4 percent.

Japanese expansion in World War II In World War II the Japanese military forces quickly took advantage of their success at Pearl Harbor to expand their holdings throughout the Pacific and westward toward India. This expansion continued relatively unchecked until mid-1942. Then, after losing the Battle of Midway, Japan slowly went on the defensive and began losing island after island. This rapid turnabout was a surprise even to the American military forces. Encyclopædia Britannica, Inc.

The overwhelming majority of Allied POWs were from Commonwealth countries; they included approximately 22,000 Australians (of whom 21,000 were from the Australian Army, 354 from the Royal Australian Navy, and 373 from the Royal Australian Air Force), more than 50,000 British troops, and at least 25,000 Indian troops. The bulk of these forces were captured with the fall of Singapore, an event widely characterized as the worst military defeat in British history. The prisoners were sent to various destinations throughout the Pacific and Southeast Asia to provide forced labour for the Japanese army, journeys that carried with them a taste of the nightmare to come. Tens of thousands of POWs were packed onto vessels that came to be known as “Hell ships”; one in five prisoners did not survive the cramped, disease-ridden journey.

A large number of the British and Australian captives were sent to Burma (Myanmar). Burma was a key strategic objective for the Japanese for two reasons. First, the Burmese city of Lashio was the southern terminus of the Burma Road, the main resupply route for Chinese during the Sino-Japanese War. The Japanese assumed that if Chiang Kai-shek’s Nationalist forces were deprived of this key logistical resource, their conquest of China could be easily completed. Second, the occupation of Burma would also put Japanese armies on the doorstep of British India. The Japanese hoped to capture the Indian region of Assam, with the intention of using it as the base for an insurrection under the Japanese-backed Indian revolutionary leader Subhas Chandra Bose. To pursue those ends and to support their continued offensives in the Burma theatre, the Japanese began construction of what came to be known as the Burma Railway.