Other than the first run, ALL other bombing runs over Japan were prefaced with warning leaflets! How could we know that our bombs would be so devastating to their infrastructure? It wasn’t the bombing that did the most damage, it was the rice-paper/wood structures that continued to burn for THREE DAYS!
More importantly, we were at war with the WHOLE of Japan! They thought of Hirohito as a GOD who had to be followed and loved! So, unlike Germany where after electing their Dictator he went crazy (although he already was, just no one noticed), Japan was WILLINGLY fighting for Hirohito! As noted by the continous 90+% death rates as we did our island-hoping campaign all the way to mainland Japan.
We're lucky that Tojo and Company didn't bump off Hirohito, before he went on the radio.
I wonder why?
We knew full and well what the buildings in Tokyo were made of and what the effect would be. We'd seen the effects after another incendiary raid on Kobe on February 4 showed similar results, and a much smaller raid on Tokyo on February 25 leveled a square mile of the city. On March 9, 1945, we sent over 300 B-29s loaded with incendiary bombs SPECIFICALLY to burn the city. The March 9th raid still stands as the most deadly aerial bombing of all time. More than Hiroshima, more than Nagasaki, more than Dresden.