Some ask why we didn't demonstrate the power of the A bomb to the Japanese to convince them to surrender. We did -- at Hiroshima! No apology is needed for that! For Nagasaki, perhaps, an apology is necessary -- from the Russians. When the US bombed Hiroshima, the Japanese approached the Soviet embassy about negotiating a surrender. Stalin sat on that plea. He desired to not only recover the southern half of the island of Sakhalin lost in the Russo-Japanese war, but much more Japanese territory, as they did in Europe. Plus, he desired to seized the munitions and arms of the Japanese army in China to give to Mao.
After Nagasaki, Japan sent an en clair message to the US pleading for surrender negotiations. Some modern historians claim the US could have easily starved Japan out -- which was true, However, how could we know that. Unlike Germany, where the allies had spies all over Germany, to include their General Staff, plus German Abwehr (intelligence) had major persons who informed the allies). Only the Soviets had spies in Japan, and they only reported to Stalin.