There were 3 issues involved in the decision to drop the bomb: 1. The battle of Okinawa was fought vigorously by the Japanese leading the allies to increase their estimates of the cost of war on the Japanese homeland. 2. The fear that if the war lasted too long then the Soviet Union would enter the pacific war and carve up Japan in the same way we carved up Germany 3. Japan's desire for a conditional surrender

It is the 3rd factor that was the crux. I believe if we understood the terms of the conditional surrender then we could have ended the war without dropping the bomb. In fact, we likely did comply with what the Japanese wanted since we protected the emperor after the war.