 The Japanese attempted to forestall them by an invasion of India (Operation U-Go), which led to a great Japanese defeat and other setbacks in Northern Burma.Following a further defeat at the hands of William Slim and the Fourteenth Army at Meiktila and Mandalay and Operation Dracula, the recapture of Rangoon, the Japanese were further handicapped in their defence of Burma.By this time the Burmese National Army under Aung San had switched sides (becoming the Burma Patriotic Army) and was hunting down Japanese patrols and foraging parties.