The bitter fighting in the jungles of SE Asia between British Commonwealth troops and the Imperial Japanese Army (IJA) was arguably amongst the most difficult of the Second WorId War. Following the Japanese invasion in December 1941, British, Indian and Australian troops fought a conventional war amidst the jungles, mangrove swamps and rubber plantations of Malaya. It quickly revealed that their combat effectiveness was shockingly low. In stark contrast, Japanese appeared well prepared for living, moving and fighting in the jungle. Within 70 days Singapore Island fell into Japanese hands along with over 80,000 prisoners. Although partially redeemed by the successful longest fighting retreat ever carried out by British arms, the Japanese invasion of Burma again showed just how badly prepared troops of the Army in Burma were for fighting in the jungles and then the more open terrain of central Burma.