I like Vox but he's dead wrong on this one. Truman wasn't a war criminal and dropping the A-bomb was necessary to end the war. Vox quotes the USSBS as follows:
" Based on a detailed investigation of all the facts, and supported by the testimony of the surviving Japanese leaders involved, it is the Surveys opinion that certainly prior to 31 December 1945, and in all probability prior to 1 November 1945, Japan would have surrendered even if the atomic bombs had not been dropped, even if Russia had not entered the war, and even if no invasion had been planned or contemplated. "
The whole problem with the "lets win the war in Nov 1945 by blockade" is it ignores several things. (1) Tens of Thousands, indeed of hundreds of thousands of Indonesians, Chinese, Filipinos, Koreans, and Indochinese were dying of starvation, disease, and combat under Japanese occupation. There was a massive land war going on in Asia and extending the war would have cost hundred of thousands of Asian lives. (2) Allied POW's were dying the hundreds in 1945 every month. Extending the war another 3 months might have cost 2,000 allied prisoners their lives. (3) We were losing 5, 000 men a month in June and July 1945. There was still air/sea war going on. Extending the war 3 months would have cost 15, 000 American lives. And I haven't even counted the UK/Australian lives that would have been lost in 3 additional months of combat. (4) Conventional bombing of Japan was killing 50,000 a month. 3 additional months would have cost the lives of 150,000 Japanese through firebombing alone.
Finally, why would the Japanese have surrendered due to a blockade alone? The answer is starvation. Which means millions of Japanese would have had to die or be on verge of dying before the Imperial Japanese would have given up. Millions of Japanese ALMOST died of starvation in 1945 when the war ended in August. Had the war ended three months later even a massive relief effort by the USA might not saved hundreds of thousands if not millions of Japanese from dying of starvation due to inadequate rice stocks.
Ending the war by blockade/conventional bombing may have been the "moral" thing to do, but it would have cost hundreds of thousand s of more lives than dropping the A-Bomb.
Probably the best two books on this subject are Downfall by Richard Frank and Japans Longest Day