Following the Japanese surrender on 15 August 1945 and the proclamation of Indonesian independence two days later, the Republic announced its first ministry on 4 September. The seventeen-member cabinet was composed mostly of 'collaborating' nationalists; Amir, appointed as Information Minister, was however, still imprisoned by the Japanese following his 1942-43 anti-Japanese underground activities. Early in the Revolution, Amir worked closely with the first Prime Minister and Sukarno's rival, Sutan Sjahrir; the two played the major role in shaping the arrangements linking the new government of Indonesia with its people remarkably effectively.