All of the information related to the Pacific theater needs be viewed as a whole.
Japan was done for. Hirohito knew it, his Generals and senior staff knew it, and the Allies knew it.
The Establishment had planned out the world's postwar map years before the end of the war - that included betraying most of Eastern Europe and China to the communists. While the allies were glad handing Chang Kai-shek with one hand, they were stabbing him in the back at Yalta with the other.
Communizing China was of much greater importance to the Establishment than was ending the war on any terms.
If more people needed to die?? So be it. If many, many more people needed to die, so be it.
Don't make the mistake of thinking that anyone in a leadership position within our government or military at that time possessed any sense of humanity in the least.
These people were hardcore psychopaths that had no qualms about killing and enslaving hundreds of millions of people. Operation Keelhaul anyone??
To contend that they would do anything for humanitarian reasons - even drop the bomb to ostensibly prevent further loss of life, is not in keeping with the character of these men.
https://thenewamerican.com/communist-ch ... n-the-usa/
Mainland China fell to Mao Tse-tung’s Communist forces in 1949, when the remnants of Chiang Kai-shek’s Nationalist army and such citizens as could escape fled to the island of Formosa, now commonly known as Taiwan. But the principal reason for the Communist takeover occurred not on the battlefield, but at the conference table, not in 1949, but four years earlier, prior to the end of World War II — and not in China, but many thousands of miles away at the Yalta summit meeting. On that occasion, unbeknownst to our ally Chiang, who was fighting well over a million Japanese troops, President Franklin D. Roosevelt promised Stalin the vast northern Chinese province of Manchuria and other concessions in exchange for Soviet entrance into the war against Japan.
The Soviet army, poised along the Manchurian border and supplied with American lend-lease equipment, entered the war against Japan three days after the atomic bomb was dropped on Hiroshima. At that late stage, noted General Albert C. Wedemeyer in his book, Wedemeyer Reports!, “the Red Army naturally met practically no enemy resistance and was soon in complete control of Manchuria” — after which “the Russians received the surrender of Japanese arms and equipment [stockpiled in the region], which they overtly and covertly made available to the Chinese Communists.” With that the balance of power in China shifted to Mao Tse-tung and his band of Communist terrorists.
You might commonly read in history books that the Chinese Communists had the upper hand over Chiang Kai-shek's Nationalists because they had been fighting the Japanese, without really any specific explanation why exactly fighting the Japanese would give them an advantage. What these history books neglect to mention is that the Soviets ensured the defeated Japanese occupation force's weapons and supplies would fall into Chinese Communist hands.
But there were other significant steps along the way that insured Chiang’s defeat and the loss of China. Those steps included the cease-fires forced upon Chiang when he was making military progress, our insistence that Chiang form a coalition government with the Communists, and our 10-month embargo on the sale or shipment of arms to Chiang.
As the end approached, Congress did pass a measure to provide some aid to China’s beleaguered anti-Communist forces, but the delivery was sabotaged. The Truman administration, wrote Wedemeyer, “succeeded in thwarting the intent of the  China Aid Act by delaying the shipment of munitions to China until the end of that critical year.” Some arms were even destroyed. As recounted by Senator Joseph McCarthy in his book America’s Retreat From Victory, “Over the hump in India, the United States military authorities were detonating large stores of ammunition and dumping 120,000 tons of war supplies in the Bay of Bengal — much of it undelivered to China but charged to her wartime lend-lease account.”
John F. Kennedy, who told the House on January 25, 1949, “The responsibility for the failure of our foreign policy in the Far East rests squarely with the White House and the Department of State. The continued insistence that aid would not be forthcoming, unless a coalition government with the Communists were formed, was a crippling blow to the national government.”
In essence, it was more like the US used a dirty trick on Chiang Kai-shek and lied to him, promising supplies if he would stop fighting the Communists, which weakened his position, but then those supplies were not sent.