At this time, as part of a compromise with the Dutch, Indonesia adopted a new federal constitution that made the country a federal state called the Republik Indonesia Serikat (Republic of United States of Indonesia), consisting of the Republic of Indonesia whose borders were determined by the "Van Mook Line", along with the six states and nine autonomous territories created by the Dutch.
During the first half of 1950, these states gradually dissolved themselves as the Dutch military that previously propped them up was withdrawn.
In August 1950, with the last state – the State of East Indonesia – dissolving itself, Sukarno declared a Unitary Republic of Indonesia based on the newly formulated provisional constitution of 1950.
Both the Federal Constitution of 1949 and the Provisional Constitution of 1950 were parliamentary in nature, where executive authority laid with the prime minister, and which—on paper—limited presidential power.
However, even with his formally reduced role, he commanded a good deal of moral authority as Father of the Nation.

The first years of parliamentary democracy proved to be very unstable for Indonesia.
Cabinets fell in rapid succession due to the sharp differences between the various political parties within the newly appointed parliament (Dewan Perwakilan Rakjat/DPR).
There were severe disagreements on future path of Indonesian state, between nationalists who wanted a secular state (led by Partai Nasional Indonesia first established by Sukarno), the Islamists who wanted an Islamic state (led by Masyumi Party), and the communists who wanted a communist state (led by PKI, only allowed to operate again in 1951).
On the economic front, there was severe dissatisfaction with continuing economic domination by large Dutch corporations and the ethnic-Chinese.

The Darul Islam rebels under Kartosuwirjo in West Java refused to acknowledge Sukarno's authority and declared an NII (Negara Islam Indonesia – Islamic State of Indonesia) in August 1949.
Rebellions in support of Darul Islam also broke out in South Sulawesi in 1951, and in Aceh in 1953.
Meanwhile, pro-federalism members of the disbanded KNIL launched failed rebellion in Bandung (APRA rebellion of 1950), in Makassar in 1950, and Ambon (Republic of South Maluku revolt of 1950).

Additionally, the military was torn by hostilities between officers originating from the colonial-era KNIL, who wished for a small and elite professional military, and the overwhelming majority of soldiers who started their careers in the Japanese-formed PETA, who were afraid of being discharged and were more known for nationalist-zeal over professionalism.

On 17 October 1952, the leaders of the former-KNIL faction, Army Chief Colonel Abdul Haris Nasution and Armed Forces Chief-of-Staff Tahi Bonar Simatupang mobilised their troops in a show of force.
Protesting against attempts by the DPR to interfere in military business on behalf of the former-PETA faction of the military, Nasution and Simatupang had their troops surround the Merdeka Palace and point their tank turrets at the building.
Their demand for Sukarno was that the current DPR be dismissed.
For this cause, Nasution and Simatupang also mobilised civilian protesters.
Sukarno came out of the palace and convinced both the soldiers and the civilians to go home.
Nasution and Simatupang were later dismissed.
Nasution, however, would be re-appointed as Army Chief after reconciling with Sukarno in 1955.

In 1954, Sukarno married Hartini, a 30-year-old widow from Salatiga, whom he met during a reception.
His third wife, Fatmawati was outraged by this fourth marriage.
She left Sukarno and their children, although they never officially divorced.
Fatmawati no longer took up the duties as First Lady, a role subsequently filled by Hartini.

The 1955 elections produced a new Parliament and a Constitutional Assembly.
The election results showed equal support for the antagonistic powers of the PNI, Masyumi, Nahdlatul Ulama, and PKI parties.
With no faction controlling a clear majority, domestic political instability continued unabated.
At this time, as part of a compromise with the Dutch, Indonesia adopted a new federal constitution that made the country a federal state called the Republik Indonesia Serikat (Republic of United States of Indonesia), consisting of the Republic of Indonesia whose borders were determined by the "Van Mook Line", along with the six states and nine autonomous territories created by the Dutch. During the first half of 1950, these states gradually dissolved themselves as the Dutch military that previously propped them up was withdrawn. In August 1950, with the last state – the State of East Indonesia – dissolving itself, Sukarno declared a Unitary Republic of Indonesia based on the newly formulated provisional constitution of 1950. Both the Federal Constitution of 1949 and the Provisional Constitution of 1950 were parliamentary in nature, where executive authority laid with the prime minister, and which—on paper—limited presidential power. However, even with his formally reduced role, he commanded a good deal of moral authority as Father of the Nation.
The first years of parliamentary democracy proved to be very unstable for Indonesia. Cabinets fell in rapid succession due to the sharp differences between the various political parties within the newly appointed parliament (Dewan Perwakilan Rakjat/DPR). There were severe disagreements on future path of Indonesian state, between nationalists who wanted a secular state (led by Partai Nasional Indonesia first established by Sukarno), the Islamists who wanted an Islamic state (led by Masyumi Party), and the communists who wanted a communist state (led by PKI, only allowed to operate again in 1951). On the economic front, there was severe dissatisfaction with continuing economic domination by large Dutch corporations and the ethnic-Chinese.
The Darul Islam rebels under Kartosuwirjo in West Java refused to acknowledge Sukarno's authority and declared an NII (Negara Islam Indonesia – Islamic State of Indonesia) in August 1949. Rebellions in support of Darul Islam also broke out in South Sulawesi in 1951, and in Aceh in 1953. Meanwhile, pro-federalism members of the disbanded KNIL launched failed rebellion in Bandung (APRA rebellion of 1950), in Makassar in 1950, and Ambon (Republic of South Maluku revolt of 1950).
Additionally, the military was torn by hostilities between officers originating from the colonial-era KNIL, who wished for a small and elite professional military, and the overwhelming majority of soldiers who started their careers in the Japanese-formed PETA, who were afraid of being discharged and were more known for nationalist-zeal over professionalism.
On 17 October 1952, the leaders of the former-KNIL faction, Army Chief Colonel Abdul Haris Nasution and Armed Forces Chief-of-Staff Tahi Bonar Simatupang mobilised their troops in a show of force. Protesting against attempts by the DPR to interfere in military business on behalf of the former-PETA faction of the military, Nasution and Simatupang had their troops surround the Merdeka Palace and point their tank turrets at the building. Their demand for Sukarno was that the current DPR be dismissed. For this cause, Nasution and Simatupang also mobilised civilian protesters. Sukarno came out of the palace and convinced both the soldiers and the civilians to go home. Nasution and Simatupang were later dismissed. Nasution, however, would be re-appointed as Army Chief after reconciling with Sukarno in 1955.
In 1954, Sukarno married Hartini, a 30-year-old widow from Salatiga, whom he met during a reception. His third wife, Fatmawati was outraged by this fourth marriage. She left Sukarno and their children, although they never officially divorced. Fatmawati no longer took up the duties as First Lady, a role subsequently filled by Hartini.
The 1955 elections produced a new Parliament and a Constitutional Assembly. The election results showed equal support for the antagonistic powers of the PNI, Masyumi, Nahdlatul Ulama, and PKI parties. With no faction controlling a clear majority, domestic political instability continued unabated.
Sukarno