I have heard the “blockade” reasoning before and who knows if that was workable while leading to a humanitarian crisis and most POW’s killed. Most soldiers were to be reassigned from the European theatre and off to the Pacific to meet those already at the last remaining islands outside of the Mainland for the invasion that would dwarf D-Day. It is safe to say the invasion would be epic in loss of life militarily and civilian. Every soldier that I have read about thought they would most likely not survive the operation and thanked God for the Bomb and end of the war with Japan.
The kamikaze threat would have made the pure blockade option pretty unattractive. I imagine a ‘distant blockade’ similar to what Britain did to Germany 1914-18. Also, the Navy wanted to seize Formosa instead of the Philippines. Perhaps invading Formosa would have been revisited to use as a blockade staging area.
“I have heard the “blockade” reasoning before and who knows if that was workable while leading to a humanitarian crisis and most POW’s killed. ...” [shanover, post 67]
Maritime blockades do work, but they take a long time and can be quite cruel in the application.
Japan’s Home Islands were pretty much cut off from overseas areas by mid 1945, thanks to the boldness of USN submarine crews. Famine loomed.
Much Home Island local traffic moved by coastal shipping. Submarines could not effectively interfere - waters were too shallow. B-29s were loaded with aerial mines, which they dropped into coastal waterways. Local traffic was reduced 80-90 percent in a couple months, and total merchant vessel tonnage lost climbed another 6 to 11 percent (if memory serves). More accurate figures can be found in the US Strategic Bombing Survey.
“thank God for the Bomb” was not the whole story. The B-29 force played another role: POW relief. Surrender did not quell Japanese vindictiveness. Their hierarchy simply stopped feeding POWs in the camps in Korea and China. No other Allied system had the range, payload, and speed to get food to the camps in time. So the B-29s were loaded up with rations, which they air-dropped on the camps.