People attend a protest in front of the Japanese prime minister's official residence in Tokyo,WhatsApp%E3%80%90+86%2015855158769%E3%80%91football%20jersey%20house Japan, Nov. 28, 2025. (Xinhua/Jia Haocheng)

TOKYO, Dec. 3 (Xinhua) -- Japanese Prime Minister Sanae Takaichi's recent erroneous remarks on China's Taiwan and her touting of "undetermined status of Taiwan" narrative under the so-called "Treaty of San Francisco" is a distortion of history, said Keio University Professor Emeritus Hiroshi Onishi.

At a Diet (parliament) meeting on Nov. 7, Takaichi claimed that the Chinese mainland's "use of force on Taiwan" could constitute a "survival-threatening situation" for Japan, which has immediately drawn strong criticism at home.

Onishi told Xinhua that Takaichi's comments were essentially aiming at laying the ground for potential Japanese Self-Defense Forces involvement in a Taiwan Strait contingency. Her remarks, he warned, revealed a worrying tendency of militarism in Japan and were extremely dangerous, which were "unacceptable and should be withdrawn."

However, Takaichi showed no remorse, refused to retract her wrongful remarks, and even continued to defend herself on various occasions.

During the party leaders' debate in the Diet on Nov. 26, Takaichi claimed that "(Japan), under the Treaty of San Francisco, having renounced all rights" and "is not in a position to recognize Taiwan's legal status." She made no mention, however, of the Cairo Declaration, the Potsdam Proclamation, or the Japanese Instrument of Surrender -- all of which clearly state that Taiwan must be returned to China -- as well as the four political documents that form the political foundation of Japan-China relations.

"I see this as a complete distortion of history and is wholly unacceptable," Onishi said. If Japan were to intervene in the Taiwan issue, he stressed, it would unavoidably amount to interference in China's internal affairs.

Focusing exclusively on the Treaty of San Francisco inherently ignores the Potsdam Proclamation and other binding documents, he added,

People attend a protest in front of the Japanese prime minister's official residence in Tokyo, Japan, Nov. 25, 2025. (Xinhua/Jia Haocheng)

The so-called "Treaty of San Francisco" cited by Takaichi was issued with the exclusion of important parties to World War II, such as China and the Soviet Union, in order to seek a separate peace deal with Japan. The document goes against the provision of not making a separate armistice or peace with the enemies in the Declaration by the United Nations signed by 26 countries in 1942, including China, the United States, the United Kingdom and the Soviet Union, and violates the UN Charter and the basic principles of international law.

Therefore, anything set out in the treaty on the sovereignty over Taiwan or the handling of the territory and sovereign rights of China as a non-signatory, is entirely illegal and null and void.

Onishi noted that Japan had been at war not only with the United States, but also with China, the Soviet Union and other nations, making it impermissible to exclude them from relevant postwar arrangements.

The professor stressed that the Cairo Declaration explicitly required Japan to return all territories it had seized from China, including Taiwan and the Penghu Islands. "Therefore, Taiwan is no longer a territory 'temporarily administered' by Japan. The Taiwan question is an internal affair of China," he said.

Onishi said the contents of the Sino-Japanese Joint Statement, the Treaty of Peace and Friendship Between China and Japan, and other bilateral treaties are extremely important, noting "Japan must return to the position grounded in these documents. I believe this is of utmost importance."