Potsdam, Germany July 26, 1945

After the conclusion of the ruinous Battle of Berlin (April 16 to May 2, 1945) and the uncon­di­tional sur­ren­der of Nazi Germany (May 7 and 8, 1945), U.S. Pre­si­dent Harry S. Truman, British Prime Minister Winston Churchill, and Soviet dictator Joseph Stalin gathered at a “Big Three” victors’ conference in Potsdam. Their meeting in a Berlin suburb from July 17 to August 2 decided the post­war geo­polit­i­cal and eco­no­mic fates of Euro­pean nations as well as that of Japan, the Axis power still fighting World War II. This Asian hold­out was upper­most in Truman’s mind as he pon­dered how to get a com­mit­ment from the leader of the Soviet Union to join the U.S., Great Britain, and China in winding down the war as quickly as pos­si­ble. For the moment the Allies were sty­mied in bringing Stalin on board by the five-year non­ag­gres­sion pact Japan and the Soviet Union had entered into in 1941.

Separate from this conundrum, Truman and Chur­chill were keen on issuing a state­ment they and Chi­nese Nation­alist leader Chiang Kai-shek could sign, sum­ma­rizing the terms and con­di­tions as the three saw it for their adver­sary’s un­con­di­tional sur­rend­er. Securing Chiang’s sig­na­ture took a good week. Late on this date, July 26, 1945, the Pots­dam Decla­ra­tion (known after its place of “pub­li­ca­tion”) was broad­cast to the world in English, then Japa­nese. Over the next few days 3 mil­lion leaf­lets that described the Allies’ terms were air­dropped over Japan. Truman and Chur­chill pur­posely kept Stalin igno­rant of the wording of the Pots­dam Decla­ra­tion (after all, his nation was a non­com­ba­tant), while secretly knowing that Stalin would declare war on Japan on August 15 “with no strings attached,” as Truman remarked to his wife on July 18, a day after learning of the Soviets’ deci­sion to enter the war. The two West­ern leaders also knew that on July 16 their joint Man­hat­tan Pro­ject had exploded an atomic bomb of the sort that could be unleashed over Japan from August 1 onward. Its use might accel­er­ate Japan’s capitu­la­tion before Soviet armies could inter­vene, thus saving millions of combatants’ lives as well as those of civilians.

The Potsdam Declaration was a final ulti­ma­tum to force Japan to accept the Allies’ uncon­di­tional sur­ren­der demands. By now Japan’s defeat was not an issue: its armed forces were whipped, yet they were esti­mated to still be lethal for up­wards of another year or more. The sticking point for Japan’s war leaders was the status of Shōwa Emperor Hiro­hito, whom Truman ini­ti­ally wanted removed in a post­war Japan. A Gallup Poll in June 1945 sided with Truman: just 7 per­cent thought Hirohito should keep his thrown, while a good third wanted him executed as a war criminal.

In its final iteration the Potsdam Declaration was ambig­u­ous enough over the emperor’s post­war fate that Hiro­hito found it “accept­able in prin­ciple.” Ignoring the signa­tories’ warning—“We shall brook no delay”—Prime Minis­ter Kan­tarō Suzuki stated at a press con­fer­ence that the decla­ra­tion was nothing more than a rehash of old pro­posals and, as such, beneath con­tempt. He would “kill (it) with silence (moku­satsu),” he said. Truman, hearing nothing back, carried out the decla­ra­tion’s threat of “prompt and utter destruc­tion” by ordering the bombing of two Japa­nese cities, Hiro­shima and Naga­saki, on August 6 and 9, 1945, using what he called “the most terrible bomb in the his­tory of the world” (Truman’s diary entry for July 25). On August 9 the Soviets dropped the final ham­mer by declaring war on Japan. Five days later Hirohito surrendered his country.

Japan 1945: Living on Borrowed Time

Potsdam Declaration: U.S. President Harry S. TrumanPotsdam Declaration: Japanese Emperor Hirohito

Left: For a brief while President Truman (1884–1972) seemed betwixt and between over his deci­sion to use the atomic bomb on Amer­i­ca’s last World War II adver­sary. The day after he ordered Hiros­hima oblit­er­ated, Truman con­fessed: “For my­self I cert­ainly regret the neces­sity of wiping out whole popu­la­tions because of the ‘pig­headed­ness’ of the leaders of a nation, and . . . I am not going to do it unless abso­lutely neces­sary.” Two days after ordering Naga­saki’s destruc­tion, Truman had no regrets: “The only langu­age they [the Japa­nese] seem to under­stand is the one we have been using to bom­bard them. When you have to deal with a beast you have to treat him as a beast.” Looking back, Truman neither shirked per­sonal respon­si­bi­lity for his deci­sion to be the only U.S. pre­si­dent to autho­rize use of a nuclear weapon nor did he apologize for it.

Right: Emperor Hirohito (1901–1989) was not directly mentioned in the Pots­dam Decla­ra­tion. The closest the decla­ra­tion came to stating the obvious wish of the victors, which was the removal of bad actors from the politi­cal and mili­tary stages after the war, was Para­graph 6: “There must be eli­mi­nated for all time the autho­rity and influ­ence of those who have deceived and mis­led the people of Japan into embarking on world con­quest.” At dawn on August 10, 1945, one day after the Naga­saki bombing and the entry of the Soviet Union into the Pacific War, the Japa­nese Foreign Minis­try, through the Swiss govern­ment, informed the U.S. State Depart­ment that the Japa­nese govern­ment was ready to accept the terms enu­mer­ated in the Pots­dam Decla­ra­tion “with the under­standing that the said decla­ration does not com­pro­mise any demand which preju­dices the pre­rog­a­tives of His Majesty as a Sover­eign Ruler.” Secre­tary of State James Byrnes responded: “From the moment of sur­ren­der the autho­rity of the Emperor and the Japa­nese Govern­ment to rule the state shall be sub­ject to the Supreme Com­man­der of the Allied Powers.” Hiro­hito was unwa­vering in his com­mit­ment to ending the war im­medi­ately and pre­pared him­self for a worst-case sce­nario in which he might be arrested by the victors, even tried and exe­cuted as a war crimi­nal. Hiro­hito kept his throne and his skin as he and Japan’s post­war govern­ment developed a well-working relation­ship with the soft-handed approach of the Supreme Com­man­der for the Allied Powers Gen. Douglas Mac­Arthur, who handed over power to the Japa­nese government in 1949.

Potsdam Conference: Truman, Churchill, Stalin in Berlin, June 1945