Operation U-Go - Origins of The Japanese Plan

Origins of The Japanese Plan

In 1942, the Japanese Army had driven the British, Indian and Chinese troops out of Burma. When heavy monsoon rains stopped campaigning, the British and Indian troops had occupied Imphal, the capital of Manipur state. This lay in a plain astride one of the few practicable routes over the jungle-covered mountains which separated India and Burma. The Japanese commander in Burma, Lieutenant General Shōjirō Iida, was asked for his opinion on whether a renewed advance should be made into India after the rains ended. After conferring with his divisional commanders, Iida reported that it would be unwise to do so, because of the difficult terrain and supply problems.

During the year and a half which followed, the Allies reconstructed the lines of communication to Assam, in north-east India. The Allies, in particular the United States created several airbases in Assam from which supplies were flown to the Nationalist Chinese government under Chiang Kai-shek and American forces in China. This air route, which crossed several mountain ranges, was known as the hump. The Americans also began constructing the Ledo road, which they intended would form a land link from Assam to China.

In mid-1943, the Japanese command in Burma had been reorganised. General Iida was posted back to Japan and a new headquarters, Burma Area Army, was created under Lieutenant-General Masakasu Kawabe. One of its subordinate formations, responsible for the central part of the front facing Imphal and Assam, was Fifteenth Army, whose new commander was Lieutenant-General Renya Mutaguchi.

From the moment he took command, Mutaguchi forcefully advocated an invasion of India. Rather than seeking a mere tactical victory, he planned to exploit the capture of Imphal by advancing to the Brahmaputra River valley, thereby cutting the Allied supply lines to their front in northern Burma, and to the airfields supplying the Nationalist Chinese. His motives for doing so appear to be complex. In late 1942, when consulted by Lieutenant General Iida about the advisability of continuing the Japanese advance, he had been particularly vocal in his opposition, as the terrain appeared to be too difficult and the logistic problems seemed impossible to overcome. He had thought at the time that this plan originated at a local level, but was ashamed of his earlier caution when he found that Imperial Army HQ had originally advocated it.

By design or chance, Mutaguchi had played a major part in several Japanese victories, ever since the Marco Polo Bridge incident in 1937. He believed it was his destiny to win the decisive battle of the war for Japan. Mutaguchi was also goaded by the first Chindit expedition launched by the British under Orde Wingate early in 1943. Wingate's troops had easily traversed terrain which Mutaguchi had earlier claimed would be impassable to the Japanese 18th Division which he commanded at the time. The Allies had widely publicised the successful aspects of Wingate's expedition while concealing their losses to disease and exhaustion, misleading Mutaguchi and some of his staff as to the difficulties they would later face.