The Second World War broke out in the year 1939 in Europe. Japan joined the war and formed an Axis with Germany and Italy. The British defence position in Burma was too weak to check the Japanese advance and so Japan occupied Burma very easily. In May, 1942, the Governor of Burma fled to Simla and established a Burmese government there. The Japanese forces released Vuamthumaung, an anti-British Zomi leader and some members of the Chin Independence Party from the Katha Jail. As soon as the Zomi politicians returned to the Zo country after crossing the dry zone of Burma on foot, they organized the Zomi freedom movement. In the meantime, Japan gave a nominal independence to Burma in 1943. Taking the opportunity the Zomi leaders declared the independence of the Zomi from the British and formed a government with Pu Vuamthumaung as its President.