The Imperial Army Turns South: the IJA’s Preparation for War against Britain, 1940–1941

Abstract

In the 18 months between the early summer of 1940 and the winter of 1941 the Imperial Japanese Army (hereinafter the IJA) spent time in close observation of new developments. The power vacuum generated in the British, French, and Dutch colonies of South East Asia by the German conquest of Western Europe in the spring of 1940 suddenly gave rise to the possibility of a war against the British, French, and Dutch as a way of seizing control over the rich natural resources under their dominion. Since its formation, the IJA’s organization and planning had continued, with its principal focus being upon Siberia and China. However, spurred on by these new developments, in 1940–41 the IJA’s focus suddenly switched southwards. In pursuing the ultimate objective of the Dutch East Indies, the advancing IJA had two obstacles to break through: In the east, the defeat of US military forces in the Philippines and the Western Pacific and the support offered thereto by the US Pacific Fleet stationed in Pearl Harbor. In the west, the Japanese forces aimed at the subjugation of the British forces stationed in Hong Kong, the Malay Peninsula, Singapore, and Burma. While the Imperial Japanese Navy (IJN) was to be principally responsible for winning the war against the Americans in the Pacific, it was to be the land battles against the British in South East Asia which the IJA troops were chiefly to deal with. According to Japanese strategic planning, the order of the invasion was to be as follows: (1) the occupation of Hong Kong, (2) the seizure of the Malay Peninsula and Singapore, (3) the exclusion of the British forces from Burma, with the Malay Peninsula and Singapore being the most important targets. Whilst leaving the overall discussion on the overall strategic planning for the IJN and IJA to Professor Kiyoshi Ikeda’s chapter in the second volume of the present series,¹ this essay outlines the IJA’s war preparations against Britain on a tactical and operational level, focusing on its invasion plan for the Malay Peninsula and Singapore.