By the middle of 1946 the violence had subsided, and the arrival of Dutch military forces meant the pro-republican forces were under pressure. The surviving elite made statements of loyalty to the Dutch and began to press for an "autonomous" East Sumatra region under Dutch protection. They were supported in this by the majority of members of the Malay, ethnic Chinese and Eurasian inhabitants. This led to plans for a plantation economy-based East Sumatran state, but without the sultans in their previous privileged positions. On 31 July 1947, a mass meeting was held in
Medan to call for the formation of a state of East Sumatra. One speaker read out a petition addressed to the Dutch
Lieutenant Governor General asking him to recognize such a state within a federal Indonesia. He also announced the formation of a Committee for an East Sumatra Special Region (
Comite Daerah Istimewa Soematera Timoer - Comite DIST) with Mansur as chairman. The Dutch began establishing the necessary bureaucracy and on August 25, a meeting was held at Mansur's house attended by DIST committee members, other supporters and Dutch officials to discuss the establishment of the state. The
State of East Indonesia (NST) was established by decree on 25 December 1947, and it was officially proclaimed on 29 January the following year, with Mansur as head of state (
Wali Negara). As head of the NST, Mansur tried to build a state that was Malay-led, but not simply a reincarnation of the old social structure headed by sultans. This caused discontent among the former aristocrats, and at the same time Mansur was unable to attract support from immigrant communities, particularly the
ethnic Javanese, who still mistrusted him. Meanwhile support for the Republic of Indonesia continued to grow. By early 1950, all the states of the
United States of Indonesia except
East Indonesia and the NST had dissolved themselves into the
Republic of Indonesia. From 3–5 May 1950, Mansur met with Indonesian Vice-president
Hatta and East Indonesian head of state
Soekowati and agreed to combine all three states into a unitary Indonesian state. On 17 August 1950, the NST ceased to exist. Tengku Mansur died five years later, in 1955. ==Notes==