South East Asia Command

South East Asia Command (SEAC) was the body set up to be in overall charge of Allied operations in the South-East Asian Theatre during World War II.

The initial supreme commander of the theatre was General Sir Archibald Wavell, initially as head of the American-British-Dutch-Australian Command, and then as British Commander in Chief India. In August 1943, the Allies created the combined South East Asian Command, to take over from British India Command stratigic responsibilities and command of the separate national commands in the theatre. In October 1943, Winston Churchill appointed Admiral Lord Louis Mountbatten as Supreme Allied Commander South East Asia, a post he held until SEAC was disbanded in 1946. The American General Joseph Stilwell was the first deputy supreme Allied commander, as well as heading the US China Burma India Theater (CBI) command.

The initial land forces operational area for SEAC was India, Burma, Ceylon, Malaya, Sumatra, and for offensive operations in Siam (Thailand) and French Indochina. On August 15, 1945 this was expanded to include the Dutch East Indies and French Indochina.

Command arrangements in SEAC were always complicated. The air forces in the region were, at first, not joined under one command. The RAF Third Tactical Air Force and the USAAF units were separate. However, by early 1944, integration was achieved. At sea, command was relatively simple, since the Royal Navy was providing almost all of the firepower in the area. Land forces were even more complicated than air forces. In theory, the British 11th Army Group, under SEAC itself, was to control all ground forces. However, US and Chinese forces serving in the South East Asian theatre were effectively in a separate formation under Stilwell, the Northern Combat Area Command or NCAC. The Eleventh Army Group had the Fourteenth Army on the Burma front, and the British garrison in Ceylon under its direct command. Stilwell took direct command of NCAC and also served as Chief of Staff to Chiang Kai-Shek, who was officially the Supreme Allied Commander in China.

It was not until late 1944 that the chain of command was clarified, after Stilwell was recalled to Washington. His overall role, and the CBI command was then split among three people: Lt Gen. Raymond Wheeler became Deputy Supreme Allied Commander South East Asia; Maj. Gen. Albert Wedemeyer became Chief of Staff to Chiang, and commander of US Forces, China Theater (USFCT). Lt Gen. Daniel Sultan was promoted, from deputy commander of CBI to commander of US Forces, India-Burma Theater (USFIBT) and commander of the NCAC. The 11th Army Group was redesignated Allied Land Forces South East Asia (ALFSEA), and NCAC was decisively placed under this formation. As the drive to liberate Burma began in earnest however, NCAC became more and more irrelevant, and it was dissolved in early 1945.

Once most of Burma was re-captured, the command turned its attention towards its next major operational objective: Malaya. However, the use of atomic bombs on the Japanese mainland brought the war to an abrupt end. The command shifted its emphasis from combat operations to military government, and the repatriation of internees and prisoners of war.

The borders of SEAC were adjusted in the aftermath of the war. French Indochina was added, along with Borneo — most of which had already been captured by Australian forces, under the South West Pacific Command — and Java. This added immensely to the problems of the command. Western governments expected SEAC to re-establish colonial regimes in territories lost to Japan in 1941-45, and in which anti-colonial, nationalist forces had gained strength.

British Commonwealth troops were landed in the East Indies and Indochina to facilitate the return of forces from the pre-war colonial powers. Military government was soon established in Burma, Malaya, Singapore and British Borneo. Sarawak and Sumatra did not prove to be major headaches for the British, except that one Japanese unit in Borneo refused to surrender until November 1945.

Thailand, although it had officially been an ally of Japan, quickly resumed both its independence and its ties with the western powers.

Because of shortages of personnel, some use was made of surrendered Japanese forces (Japanese Surrendered Personnel) in these areas. The Allies found that their war-time allies in the Viet Minh in Indochina, and Indonesian nationalist forces in the East Indies, were well armed, well-organised and determined. It was intended that British forces would temporarily enforce military government over a small section of Indochina, because of local resistance, logistics and French sensibilities. However, in the end the commander of British forces declared de facto military government, to make it possible for French forces to return.

In Java, Japanese forces had armed Indonesian nationalists. It only proved possible for British forces to establish military government on part of the island, and they found that the location of Allied prisoners of war — and civilians interned by Japanese forces — were sometimes used by nationalists in bargaining for political ends.

As 1946 drew on, SEAC discharged its final tasks and was disbanded. It was no longer felt that a joint command was needed in the area.