British Burma

In 1934, Ba Maw served as education minister, and then in 1937, he became premier under the new Burmese constitution. In July 1940, Ba Maw resigned from the Legislature of Burma. During a conference of the Sinyetha, he issued seven orders, one of which was, "to refuse to participate in the war in any way as long as freedom was refused to the Burmese." On 6 August 1940, he was arrested for violating the Defence of Burma Rules, and taken to Mandalay for trial.^[7]

According to Ba Maw, "My trial in itself was a ritual sort of affair, brief and formal and without any touch of drama in it. All the drama was taking place outside [...] where people everywhere had begun to speak with greater racial feeling and defiance." On 28 August, Ba Maw was found guilty and sentenced to imprisonment for a year. Originally jailed in Mandalay, he was later relocated to Mogok, in northern Burma.^[7]

Burma under Japanese Occupation

The Greater East Asia Conference in November 1943. The participants were (L–R): Ba Maw, Zhang Jinghui, Wang Jingwei, Hideki Tojo, Wan Waithayakon, José P. Laurel, Subhas Chandra Bose

On 13 April 1942, Ba Maw escaped from Mogok during the Thingyan festival. He and his wife Khin Ma Ma Maw hid out in the hills of Mang Lon until the third week in May, when they established contact with the Japanese. On 4 June, during the Japanese occupation of Burma, Ba Maw was made Chief Civilian Administrator, while Aung San agreed to reform the Burmese Independence Army as the Burma Defense Army. On 1 August 1942, Ba Maw was inaugurated as the head of the Burmese government.^{[7]: 192, 235–261}

As the war situation gradually turned against the Japanese, the Japanese government advanced its previously vague promise to grant Burma independence after the end of the war.^[8] The Japanese felt that this would give the Burmese a real stake in an Axis victory in the Second World War, creating resistance against possible re-colonization by the western powers, and increased military and economic support from Burma for the Japanese war effort. A Burma Independence Preparatory Committee chaired by Ba Maw was formed 8 May 1943.^[9]

The nominally independent State of Burma was proclaimed on 1 August 1943 with Ba Maw as "Naingandaw Adipadi" (head of state) as well as prime minister. The new state quickly declared war on the United Kingdom and the United States, and concluded a Treaty of Alliance with the Empire of Japan. Ba Maw attended the Greater East Asia Conference in Tokyo in November 1943, where he made a speech speaking of how it was the call of Asiatic blood that drew them together into a new era of unity and peace.^[10]

Dissatisfied with him, in 1944 a secret clique within the Imperial Japanese Army made up of Kawabe, Isomura and Ozeki decided to hatch a conspiracy to get rid of Ba Maw and replace him with U Nu. The clique contacted U Nu, but U Nu disagreed with the plan and notified Ba Maw of the plot. Although the conspiracy only involved a few officers and not the entire Imperial Japanese Army, this fact fueled Ba Maw's distrust of his Japanese allies. However, he decided to continue collaborating with them until the end of the war because he believed that the priority was to ensure the independence of the British Empire.

During their rule, these Japanese soldiers supported the demonstrations in support of the restoration of the monarchy that took place in Shwedagon. According to Ba Maw, Japanese militarists believed that a puppet monarchy similar to Manchukuo would be easier to manage and better serve their interests. The military viewed Taw Phya Gyi, eldest grandson of Thibaw, last king of Burma, as the favorite candidate to occupy the throne. Taw Payagyi was a young man with no experience or aspirations and no political background, so he was just the kind of easy-to-control nominal Head of State they were looking for.^[11]

However, the new state failed to secure popular support or diplomatic recognition due to the continued presence and activities of the Imperial Japanese Army, and after their collaborationist allies, the Burma National Army defected to the Allies side, the government collapsed.

Ba Maw fled just ahead of advancing British forces via Thailand to Japan, where he was captured ^[12] later that year by the American occupational authorities and was held in Sugamo Prison until 1946.

Independent Burma

Ba Maw was allowed to return to Burma, after Burma became independent of the United Kingdom. When he returned to Burma in August 1946, he was invited by Aung San to join the AFPFL and take an important post in the newly independent government, but Ba refused and reorganized the Mahabama Party as an opposition force.^[13] He remained active in politics. He was jailed briefly during 1947, on suspicion of involvement in the assassination of Aung San, but was soon released.

After General Ne Win (1910–2002) took over power in 1963, Ba Maw was again imprisoned (like many prominent Burmese of the period who were detained during the time of Ne Win regime, from the 1960s to the 1980s, his imprisonment was without charge or trial) from about 1965 or 1966 to February 1968. During the period of his imprisonment Ba Maw managed to smuggle out a manuscript of his memoirs of the war years, during less than two of which (from 1 August 1943 to March 1945) he was Head of State (in Burmese naing-ngan-daw-adipadi, lit. 'paramount ruler of the State').

He never again held political office. His book Breakthrough in Burma: Memoirs of a Revolution, 1939–1946, an account of his role during the war years, was published by Yale University Press (New Haven) in 1968. In the post-war period he founded the Mahabama (Greater Burma) Party. He died in Rangoon on 28 May 1977.