On August 6, 1945 an atomic bomb was dropped on the Japanese city of Hiroshima by the United States which began to demoralize the spirit of the Japanese soldiers all over the world. A day later Investigation Agency Preparation for Indonesian Independence BPUPKI, or "Dokuritsu Junbi Cosakai", renamed PPKI (Committee for Indonesian Independence) or also called Dokuritsu Junbi Inkai in Japanese, to further confirm the desire and goal of achieving the independence of Indonesia. On August 9, 1945, the second atomic bomb dropped on Nagasaki, causing the Japanese surrendered to the United States and its allies. This moment is also used by Indonesia to declare its independence.
The raising of the flag on August 17, 1945. Sukarno, Hatta PPKI as leader and as a former chairman Wedyodiningrat Radjiman BPUPKI flown to Dalat, 250 km northeast of Saigon, Vietnam to meet with Marshal Terauchi. They reported that Japanese troops were on the verge of defeat and will give independence to Indonesia. Meanwhile in Indonesia, on August 10, 1945, Sutan Syahrir have heard over the radio that the Japanese had surrendered to the Allies. The underground fighters preparing to proclaim independence, and rejected the independence given as a gift of Japan.
On August 12, 1945, Japan by Marshal Terauchi in Dalat, Vietnam, told Sukarno, Hatta and Radjiman that the Japanese government will soon grant independence to Indonesia and the proclamation of independence can be implemented within a few days, depending on how the PPKI.  Despite this Japan wanted the independence of Indonesia on August 24.
Two days later, while Sukarno, Hatta and Radjiman back to the homeland of Dalat, Sutan Syahrir urged Sukarno declared independence immediately because it considers the results of the meeting in Dalat as a ruse Japan, because Japan every moment has to be surrendered to the Allies and to avoid a split in nationalist camp, between the anti-and pro-Japanese. Syahrir Hatta told about the results of the meeting in Dalat. Sukarno did not yet convinced that the Japanese had surrendered, and the proclamation of independence of Indonesia when it could cause great bloodshed, and can be fatal if the fighters Indonesia was not ready. Soekarno Hatta warned that Syahrir not entitled to declare independence because it is the right of the Preparatory Committee for Indonesian Independence (PPKI). Meanwhile Syahrir agency considers PPKI is made in Japan and the proclamation of independence by PPKI just a 'gift' from Japan (sic).
Indonesian flag being raised on August 17, 1945. On August 14, 1945 Japan surrendered to the Allies. Army and Navy of Japan was still in power in Indonesia because of Japan has promised to restore the power in Indonesia into Allied hands. Sjahrir, Wikana, Dervish, and Chaerul Saleh heard this news through BBC radio. After hearing rumors of Japan would be to its knees, the young group urged the elderly to be proclaimed Indonesian independence. However, the elderly do not want to rush. They do not want the bloodshed at the time of the proclamation. Consultation was carried out in the form of PPKI meeting. Young Group does not approve of the meeting, given PPKI is a body established by the Japanese. They want independence for our nation's own efforts, not giving Japan.
Sukarno and Hatta went to military rulers of Japan (Gunsei) to obtain confirmation in his office in Koningsplein (Merdeka Square). But the office was empty.
Sukarno and Hatta with Soebardjo then to the office Bukanfu, Rear Admiral Maeda, in Jalan Medan Merdeka Utara (Maeda house on Jl Imam snag 1). Maeda welcoming them with congratulations on their success in Dalat. As he said he has not received confirmation, and are still waiting for instructions from Tokyo. Coming home from Maeda, Sukarno and Hatta immediately prepare for the meeting of the Preparatory Committee for Indonesian Independence (PPKI) on August 16 at 10 am the next day at the office Pejambon Road No. 2 to discuss all things related to the preparation of the Declaration of Independence.
A day later, the pressure fluctuation which requires the taking of power by mounting Indonesia launched the youth of some classes. PPKI meeting on August 16 at 10 am was not implemented because of Sukarno and Hatta did not appear. The meeting participants do not know the event has occurred Rengasdengklok.