The Japan-China Joint Communiqué and the Question of Taiwan – The Diplomat

Tensions are rising in China-Japan relations over Taiwan. It started with Prime Minister Takaichi Sanae’s statement to the Diet on November 7, 2025, in which she indicated that Japan could exercise its right of collective self-defense to mobilize the Self-Defense Forces if China used military force against Taiwan. The Chinese government’s response was harsh, saying that Japan had suggested it might intervene in the Taiwan issue with military force. It also emphasized that “Taiwan is an inalienable part of the territory of the People’s Republic of China,” and is pressuring the Japanese prime minister to retract her comments with a clutch of coercive economic measures.

Among the contested issues in China-Japan relations, Taiwan occupies a unique position. It has remained the most important issue between Japan and China since the founding of the People’s Republic of China (PRC) in 1949, while other historical and territorial disputes only emerged after the end of the Cold War. To understand the Japanese government’s position on the Taiwan issue today, we need to look back at the 1972 negotiations on the normalization of diplomatic relations and examine what each country agreed.

When diplomatic relations between Japan and China were normalized in September 1972, the Japanese government affirmed that the PRC was the “sole legal Government” of China. This “terminated” the Treaty of Taipei, and the foreign minister at the time announced that diplomatic relations with Taiwan (Republic of China or ROC), which Japan had maintained since 1952, would be severed in favor of new diplomatic relations with the PRC.

With the normalization of diplomatic relations between Japan and China, the most significant point of contention was the legal status of Taiwan. China has always asserted that “Taiwan is an inalienable part of the territory of the People’s Republic of China,” but the Japanese government chose not to accept this position.

The real issue for Japan was how to achieve a compromise with China. When Canada and Italy recognized the PRC in the autumn of 1970, they issued a joint communiqué that used the phrase “take note” regarding China’s territorial claim over Taiwan. With the Shanghai Communiqué in February 1972, the U.S. “acknowledged” China’s claim, while also stating that it “does not challenge that position.” Over time, Beijing was seeking stronger support for its Taiwan claims.

Japan used the Netherlands’ establishment of diplomatic relations with China in May 1972 as a reference. In the joint communiqué with China, the Netherlands stated that it “respected” the Chinese position and “recognized” the PRC as the sole government of China. Based on this precedent, Japan’s Ministry of Foreign Affairs decided to negotiate with China by stating that it “understands and respects” China’s position.

However, during negotiations in Beijing in September 1972, China rejected Japan’s wording. Instead, it proposed the following wording: “The Government of Japan supports China’s position based on the Cairo Declaration.” But endorsing the Cairo Declaration would contradict the Japanese government’s position under the San Francisco Peace Treaty, as it would promise the return of Taiwan and the Penghu Islands to the ROC. The San Francisco Peace Treaty renounced Japan’s sovereignty over Taiwan and the Penghu Islands but did not settle their legal status. As a result, Japan refused to accept the proposed wording.

The third paragraph of the Japan-China Joint Communiqué was adopted following a revised proposal from Japan. It read: “The Government of the People’s Republic of China reiterates that Taiwan is an inalienable part of the territory of the People’s Republic of China. The Government of Japan fully understands and respects this stand of the Government of the People’s Republic of China, and it firmly maintains its stand under Article 8 of the Potsdam Proclamation.” According to former Ambassador to the United States Kuriyama Takakazu, who at the time was serving as Director of the Treaty Division of the Ministry of Foreign Affairs and who was involved in drafting the joint communiqué, this wording was structured to show indirect support for the Cairo Declaration by referring to the Potsdam Proclamation, which Japan had accepted and which in turn referenced the Cairo Declaration.

Since then, the Chinese government has continued to assert that, through the normalization of diplomatic relations between Japan and China, Japan has accepted the position that “Taiwan is part of China.” However, this interpretation is not accurate. The Japanese government took the position that while it “understands and respects” China’s “One China” principle, it has never legally recognized China’s territorial claims over Taiwan. Additionally, as Foreign Minister Ohira Masayoshi responded to questions in the Diet in November 1972, the Japanese government has fundamentally positioned the Taiwan issue as an internal Chinese affair, while not explicitly excluding Taiwan from the Japan-U.S. Security Treaty and reserving its position in the event of armed conflict.

Behind the Japanese government’s decision is the fact that Japan effectively allowed the use of U.S. military bases in Japan in the event of a Taiwan emergency under the Taiwan clause found within the Japan-United States Joint Statement of 1969. Japan has paid careful attention to ensure that the development of relations with China did not weaken the Japan-U.S. Security Treaty.

Japan and China were not entirely in sync over Taiwan when they normalized diplomatic relations. From this perspective, the normalization of diplomatic relations between the two countries was a modus vivendi established without resolving differences in their interpretations of the Taiwan question. During the 1970s, China lacked the ability to invade Taiwan, so these differences in interpretation could be kept on the back-burner. However, China’s growing military power since the last decade is changing the context. The current spat sparked by Takaichi’s comments has shown that the modus vivendi established through the normalization of diplomatic relations is nearing its limit.