I wish your campaign fortune. It would be an unmitigated blessing if mankind somehow, despite all its perennial flaws, universally agreed never to use what Churchill called “these awful agencies of destruction.”

War itself being a crime against humanity, it is a little redundant to identify specific parts of it as the same thing. I explained Churchill’s and Truman’s views, too superficially I fear, based on what they knew at the time.

Professor Williamson Murray, in a 2015 lecture at Ohio State, is more thorough, analyzing the bombing decision based on what we now know. Click here and skip to start at minute 7:

Murray reminds us that it’s a very frequent habit these days for historians and others to engage in Monday morning quarterbacking. What they often miss—when recommending what we should have done instead of what we did—is that it might have led to something even worse.

I found interesting his documentation that US (20,000) and Japanese (77,000) deaths in Okinawa, a three-month battle, were close to the number of Americans killed in all twelve years of the Vietnam War, not to mention Vietnamese; and that the estimate of “only” 50,000 U.S. casualties in taking Kyushu were made in May, when Japan had 100,000 troops there….by August Japan had 450,000, plus 5000 Kamikaze aircraft ready to go.

You are right to identify the threat of starvation, but perhaps not the extent of that threat—particularly if it was decided not to drop the bombs. By mid-1945, it was already known that knocking out transportation had been the most productive aspect of the air war on Germany. In an extended campaign in Japan, one of the first objectives would have been its transportation facilities, which were vulnerable and relatively easy to destroy. What would that have led to? It’s not hard to imagine:

By summer 1945, the Japanese were rationed to 1200 calories a day, the edge of starvation. As you state, the situation continued long afterward. Murray notes that even in 1946, General MacArthur (for once “the good MacArthur”) had to urge President Truman to send massive food aid or risk going down in history as the starver of 3-5 million people. Truman did so, and Japan’s transportation system was intact to deliver it. As a result a catrastrophe far worse, and longer lasting, was averted.

We must always, as they say, be careful what we wish for.

Ah, there’s the rub. The imminent entry of Russia into the war against Japan was a spur to Truman, who worried how far they might go. But the Japanese cabinet was still not unanimous for surrender after Nagasaki. It took the emperor, at risk of his life (indeed a coup was tried but failed), to decide to surrender.