promoted to colonel in 1960, and was appointed as the Penguasa Perang (literally War Ruler) of the Mainland Riau Region and the commander of the Wirabima Military Command, which covered the territory of Riau. At the same year, Nasution was promoted to brigadier general, and became the Penguasa Perang of the Riau Province. As the warlord of the province, he automatically became the chairman of the Executive Body (Badan Pelaksana) of the Riau Province. With this position, Nasution was formally inaugurated as the governor of Riau on 6 January 1960, replacing Sutan Mohammad Amin. The Executive Body was dissolved and was replaced by a Daily Government Body (Badan Pemerintahan Harian, BPH). The BPH was later tasked to form the Regional People's Representative Council of Mutual Assistance in the Riau Province. The composition of the council was based on the results of the 1955 Indonesian legislative election. Alongside the BPH, Nasution also created the post of Deputy Governor to assist him. He appointed Datuk Wan Abdulrachman on 25 April 1962 for the position, but he soon opposed Nasution after Nasution accused him of cooperating with Malaysia during the Indonesia–Malaysia confrontation period. Nasution would later arrest him under the accusation of participating in the United Republic of Indonesia, a secessionist movement. As the Governor of Riau, Nasution concurrently held several positions during his term, namely as the Speaker of the Regional People's Representative Council of Riau from 1961 until 1966, the honorary office as the Chairman of the Rectorate Council of the Islamic University of Riau and the Riau State University from 1963 until 1966, and as the chairman of the National Front branch of Riau and the '45 Struggle Organization. He also became the member of the People's Consultative Assembly from 15 September 1960 until his removal from office on 15 November 1966. During his tenure as the Governor of Riau, President Sukarno ordered him to move the capital of Riau from Tanjungpinang, which at that time was still using Singapore dollar, to the newly liberated Pekanbaru, which already was using the Indonesian Rupiah. Upon hearing this news, many Riau civil employees refused to be moved to Pekanbaru, and opted to resign instead. Assisted by Ahmad Faqih, an expert in public works, Kaharuddin planned Pekanbaru as a modern city. Kaharuddin modeled the Pekanbaru after the New York City, with a road system in the form of streets and avenues. After building