This article examines the Yalta secret agreements of 1945, in which the United States approved Soviet sovereignty over southern Sakhalin and the Kuril Islands. It traces Stalin’s reaction, Roosevelt’s calculations, Japan’s reliance on the Soviet–Japanese Neutrality Pact, and the ignored U.S. State Department memorandum that warned against conceding the southern Kurils.

The following is taken from an article titled “The Secret Deal. Stalin Rejoiced,” published on page three of yesterday’s Sankei Shimbun.
2016-11-27.
What follows is a continuation of the previous chapter.
The following is taken from an article titled “The Secret Deal. Stalin Rejoiced,” published on page three of yesterday’s Sankei Shimbun.
The Northern Territories.
The secret deal that made Stalin rejoice.
In February 1945, Showa 20, the leaders of the United States, Britain, and the Soviet Union gathered at the resort of Yalta on the Crimean Peninsula and decided the postwar division of the world.
This was the Yalta secret agreement, which continues to cast a dark shadow over the postwar world.
The Soviet dictator Joseph Stalin established his quarters at the Yusupov Palace.
On the morning of February 8, Stalin repeatedly cried out in triumph in his study.
“Khorosho. Ochin.”
What he clutched in his hand was a letter from U.S. President Franklin D. Roosevelt.
It stated, “The U.S. government recognizes Soviet sovereignty over southern Sakhalin and the Kuril Islands currently under Japanese occupation.”
At an informal meeting between the American and Soviet leaders, the handling of the Kuril Islands was also readily approved.
There had been a prelude to this.
On October 5, 1943, Showa 18, Roosevelt summoned senior government officials, including Secretary of State Cordell Hull, to the White House.
“In exchange for Soviet entry into the war against Japan, the Kuril Islands should be handed over to the Soviet Union.”
Roosevelt proposed this.
He feared that continued Japanese resistance would increase American casualties.
No expectation of Soviet entry.
However, Japan had not anticipated Soviet entry into the war against it.
This was because Japan trusted the Soviet–Japanese Neutrality Pact concluded on April 13, 1941, Showa 16.
Negotiations toward concluding the treaty between the two governments had begun in 1940, Showa 15.
Japan’s representative was Foreign Minister Yosuke Matsuoka, and the Soviet representative was Foreign Minister Vyacheslav Molotov, although Stalin himself also appeared.
Stalin pressed Matsuoka, saying, “I want southern Sakhalin and the Kuril Islands returned.”
Matsuoka refused, but as the German army pressed closer, the Soviet Union grew anxious and withdrew its demand.
The United States grasped the Soviet–Japanese treaty negotiations through codebreaking.
It had known from that time that the Soviet Union was aiming at the Kuril Islands.
Within the U.S. government, some officials had already recognized the strategic importance of the Kuril Islands.
On December 6, 1944, Showa 19, about two months before the Yalta Conference, the U.S. State Department’s Division of Territorial Studies submitted a top-secret document, the Breaksley Memorandum, to Roosevelt.
“The southern Kuril Islands should be retained by Japan.”
“There is little justification for Soviet claims to the southern islands.”
However, Roosevelt paid no attention.
To be continued.