"The alternative for Japan is prompt and utter destruction."

The Potsdam Conference & Declaration

76 years ago yesterday, on July 26, 1945, Allied leaders released the Potsdam Declaration, an ultimatum addressed to Japan. The declaration was part of the proceedings of the Potsdam Conference going on at the time, whose purpose was to lay out the new world order after World War II.
 
The conference, lasting from July 17 to August 2, was held right outside Berlin, and was the last in a series of Allied conferences where American, British and Soviet leaders planned out the course of the war. In July 1945, the end was in sight. Nazi Germany has already surrendered in May. Italy changed sides back in 1943. Germany's other European allies have been conquered by the Soviet Union. Japan was still fighting on, but was pushed back to the Japanese Home Isles, and their eventual defeat was clearly inevitable. The big question at Potsdam was not how to continue the war, but what to do afterwards. And, while the war was coming to an end, more trouble was on the horizon.

One sign of the new times was the identities of the participants. President Roosevelt died in April, and his Vice President, Harry Truman, assumed his position. When the conference began, the British delegation was headed by Winston Churchill, but he was no longer around by the time it ended. The 1945 general election in the UK was held on July 5, but the votes were only counted on the 26th to allow for soldiers' overseas votes to be transported home. On the 26th, it turned out that Churchill's Conservative Party has lost the election. His Labour Party successor, Clement Attlee, replaced Churchill not only as head of government, but also as leader of the British delegation to Potsdam. The only Allied leader whose identity did not change throughout the war was Joseph Stalin.

At Yalta, the previous big conference in February of the same year, it was agreed that European countries will get to have free elections to decide their own futures. However, with Central and Eastern Europe under Soviet occupation, it was becoming clear that Stalin had no intention of honoring this earlier agreement, and was going to install Communist puppet governments.

With Hitler no longer around as a common enemy, differences in interest between the Allies became much more pronounced, and Truman was also taking a harder stance in his arguments with Stalin than Roosevelt ever did. Roosevelt and Stalin got along at the negotiating table relatively easily, largely due to Roosevelt's belief that Stalin was going to be a man of his word regarding agreements and promises. In contrast, Churchill's British imperial worldview and values have always clashed with Stalin's Communism.

Stalin saw Nazi Germany wreak devastating damage on his country, and was determined to extract enormous economic reparations to rebuild the Soviet Union. He was also planning to draw Central and Eastern Europe into the Soviet sphere of influence and use them as a protective shield against any possible future invasion from European countries.
 
Truman, who fought in Europe in World War I, had a different perspective. Besides distrusting Stalin, he also believed that the harsh peace treaties imposed on Germany after World War I were largely the reason why Hitler could ride a wave of economic hardship and popular discontent to power, eventually leading to World War II. Truman believed that similarly harsh terms, which Stalin was likely to go for, would lead to history repeating itself and plunging Europe into a third World War.

Therefore, the question of war reparations became a pivotal point of contention at Potsdam, and Truman managed to reach a compromise. The partition of Germany and Austria into separate zones, each administered by one of the Allies (America, Britain, the USSR and France) was already agreed on at Yalta. In Potsdam, the participants agreed to limit each occupier to their own zones in terms of reparations: in short, they could only take items from those parts of the country that they controlled. The Soviets, however, were given a special exemption and could also take 10% of the country's industrial capacity from every other zone. This was meant literally: Over the course of two years, the Soviets would remove industrial machinery all over Germany and transport it east.

Another major talking point was the fate of Poland. Early in the war, the USSR invaded Poland (which was already under attack by Germany) and occupied a significant part of it in the east. Since the Soviets were on the Allied side, there was no question of them giving any of that back. However, Poland was still a victim of German (as well as Russian) aggression and had to be compensated; not doing so would have thrown the moral superiority of the Allies into question. The solution was to "push" the entire country west. Russia got to keep Eastern Poland, but the Allies carved a comparably-sized area of land off Germany and gave it to Poland as compensation.

Much of the rest of the Potsdam conference dealt with what historians call the "Four Ds": the demilitarization, denazification, decentralization and democratization of Germany.  Demilitarization obviously referred to the disarmament of German armed forces, but also to the destruction of German fortifications and war industry. Denazification most famously included the military tribunals at Nuremberg, where German war criminal were tried and sentences. The term also refers to a much more widespread procedure, in which many Germans – officials, businessmen, politicians and the like – had to undergo extensive background checks to determine their ties to the Nazi Party, which could earn them various levels of sanctions from travel and employment restrictions through fines to jail time. Decentralization was, in a way, not so much a political reform as a return to an earlier arrangement. Germany's predecessor, the Holy Roman Empire, was a greatly decentralized state, but both the Weimar Republic and the Third Reich placed a great deal of power in the hands of the central government. The post-war reforms saw the introduction of a federal system not entirely unlike the states of the USA. Finally, democratization referred to the eventual reconstruction of a democratic and peaceful Germany. This last goal was achieved in 1949, with the West German federal election. (Stuck under Soviet domination, East Germany obviously failed to become a democratic society.)

But what about Japan? Though the island nation was still holding out, the end was in sight. The Trinity test, the famous first-ever detonation of an atomic bomb, occurred on July 16, the day before the conference began. Operation Downfall, the conventional invasion of Japan, was likely to involve appalling casualties, so Truman hoped that Japan could be cowed into surrender by the deployment of nuclear weapons. The Potsdam declaration was drafted as an ultimatum: a last chance for Japan to surrender. Should they refuse to do so, atomic bombing would follow.

The declaration made several demands:

• The elimination "of the authority and influence of those who deceived and misled the people of Japan into embarking on world conquest"
• The occupation of "points in Japanese territory to be designated by the Allies"
• Limiting Japanese sovereignty to the four main islands of Honshu, Kyushu, Shikoku and Hokkaido, "and such minor islands as [the Allies] determine"
• Disarmament of Japanese military forces and their return to civilian life.
• Meting it out justice to war criminals.

 
The terms were deliberately kept ambiguous to give the Allies a free hand if and when the Japanese surrendered. This, however, made it much harder for the Japanese to accept the demands. Exactly which parts of Japan would fall under occupation? Exactly which islands would Japan get to keep? (To put the question in perspective: Japan today has close to 7,000 islands, about 430 of which are inhabited. With such number, the phrase "such minor islands as we determine" was extremely vague.) And perhaps most importantly: what about Emperor Hirohito, who, according to traditional Japanese thinking, was a divine figure? Would the Allies consider him one of the individuals "who deceived and misled" Japan, or would he be part of "a peacefully inclined and responsible government", which the ultimatum promised?

The ultimatum was never delivered to Japan through official diplomatic channels. Instead, it was broadcast on radio in English and Japanese, and 3 million leaflets of the declaration were dropped over Japan.
 
The declaration spurred hot debate within the Japanese government. Prime Minister Kantarō Suzuki, Foreign Minister Shigenori Tōgō and Cabinet Secretary Hisatsune Sakomizu all agreed that the ultimatum should be accepted, even though Tōgō did think that the terms were too ambiguous. He suggested contacting the Soviet Union, which has never actually declared war on Japan and was not fighting against it, and asking it to act as a mediator between Japan and the Western Allies to help clarify the terms. The Prime Minister met Emperor Hirohito and suggested that a reply should be postponed until they hear back from the Soviets. Hirohito stated his opinion that the declaration was "agreeable in principle". Meanwhile, the Supreme Council for the Direction of the War met on the same day with military leaders declaring the ultimatum unacceptable and leading to a schism in Japanese leadership.

Time ran out for Japan while they were waiting for a Soviet reply. Hiroshima was bombed on August 6, and Nagasaki on August 9. On the same day, Stalin withdrew from the neutrality pact with Japan and declared war. With no hope for further negotiations, Japan had no choice but to surrender the next day.