The recent escalation of tensions between Japan and China has revived and intensified a perennial debate on the international legal status of Taiwan. Japanese prime minister Sanae Takaichi drew a vociferous response from Beijing when she said publicly in early November that a Chinese use of force against Taiwan could be deemed “a situation that threatens Japan’s survival,” implying that it might lead to Japanese military intervention.

The Chinese have since demanded that she retract her statements, insisting that the Taiwan issue is an internal Chinese affair in which no foreign country can interfere, and that Takaichi has violated prior Japanese acceptance of the idea that Taiwan is part of China. Chinese president Xi Jinping, in a subsequent conversation with President Donald Trump—no doubt aimed at getting Trump to press Takaichi to retreat—stated that “Taiwan’s return to China [after the defeat of Japan in World War II] is an integral part of the post-war international order.”

Understanding the context and significance of this episode and Xi’s statement requires a brief history lesson. Taiwan was incorporated into the Chinese empire in the 17th century, but the emperors paid it only episodic attention and usually had trouble exercising full control over it. It wasn’t until 1887 that Taiwan was designated a Chinese province. 

Shortly thereafter, it was annexed and colonized by Japan following the Sino-Japanese War of 1894–95. While Taiwan was under Japanese control, the Chinese empire collapsed, and the “Republic of China” (ROC) was established in 1912. But mainland China then devolved into an intermittent civil war between the Nationalists (ROC) and the Communists, which was interrupted by World War II.

During the war, the United States was allied with the ROC against Japan. A crucial benchmark occurred in November 1943, when Franklin Roosevelt, Winston Churchill, and ROC leader Chiang Kai-shek issued the “Cairo Declaration,” which stated that “all the territories Japan has stolen from the Chinese”—including Taiwan—would be “restored to the Republic of China” after the war. This was reaffirmed by the same three leaders in the “Potsdam Declaration” of July 1945. And this is the basis for Xi Jinping’s statement to Trump that “Taiwan’s return to China” was integral to the post-war order.

But then the ground shifted. The Chinese Civil War resumed, and the Communists won, establishing the People’s Republic of China (PRC) in 1949. The Nationalists fled to Taiwan and maintained the ROC there as a rival Chinese government—still recognized by both the United States and Japan. And although Japan had been forced to renounce its claim to Taiwan, and the ROC had accepted the Japanese surrender of the island on behalf of the United States and its allies, sovereignty over Taiwan was never formally transferred to any power. When the Korean War broke out in 1950, President Truman declared that “The determination of the future status of [Taiwan] must await the restoration of security in the Pacific, a peace settlement with Japan, or consideration by the United Nations.” This was part of the basis for the view today that Taiwan’s status remains “undetermined.”

Returning to the present situation: proponents of Taiwan’s “undetermined” status rarely address the question of who or what will ultimately determine it and under what circumstances. As just noted, Truman in 1950 provided three options. “Security in the Pacific” arguably was restored with the Korean armistice, but that did not bring any formal adjudication of Taiwan’s status. 

The peace treaty with Japan, signed in San Francisco in 1952, confirmed Tokyo’s surrender of sovereignty over Taiwan, but also did not formally transfer it to the ROC or any other entity—largely because the Chinese Civil War remained unresolved and other countries were working out how to deal with........

© The National Interest