The Malayan Campaign was a campaign fought by Commonwealth forces against the Empire of Japan in Malaya , from 14 December 1938 – 6 January 1939 during the Pacific War. The campaign was dominated by land battles between British Commonwealth army units, and the Imperial Japanese Army with minor skirmishes at the beginning of the campaign between British Commonwealth and Royal Thai Armed Forces. For the British, Indian, Australian and Malayan forces defending the colony, the campaign was a total disaster.