Introduction

China has reacted furiously to Japanese Prime Minister Sanae Takaichi’s remarks in the Diet, and the issue has escalated into a major diplomatic dispute, with both Tokyo and Beijing summoning each other’s ambassadors and trading accusations. At the heart of China’s loud rhetorical offensive is its claim that the Japanese leader’s remarks violated the “One China” principle. But is that really the case?

Regarding this “One China” issue, not only has the Chinese side engaged in self-serving and unfettered interpretations, but misunderstanding and confusion can also be seen in discussions within Japan’s Diet and among experts. I would like to take this opportunity to trace the historical background, examine the facts, and offer one perspective for considering how Japan should respond going forward.

Background behind the issue

What the Chinese government has taken issue with is Prime Minister Takaichi’s remarks during the House of Representatives Budget Committee session on November 7, 2025. Regarding the Taiwan issue, she stated that Japan’s position is to “expect a peaceful resolution,” and explained that which sort of situation would constitute a survival-threatening crisis (under which collective self-defense could be exercised) would be determined on the basis of prevailing circumstances. She then added that “one could imagine a situation in which China imposes a naval blockade around Taiwan with warships and US forces come to assist, resulting in the use of force.” She emphasized that “it is important to anticipate a minimum and worst-case scenario,” noting that “if warships are used, it could constitute a survival-threatening crisis.” [1]

In response, the Chinese Embassy in Japan was the first to react. On November 12, it issued a spokesperson’s statement criticizing Prime Minister Takaichi’s reference to a Taiwan contingency as “a survival-threatening crisis,” calling it “a blatant and provocative remark, a reckless interference in China’s internal affairs, and a challenge to China’s core interests.” The statement further warned that “external forces must not interfere in the Taiwan issue, and any attempt to intervene will only result in burning themselves.” [2]

Furthermore, on the following day, November 13, Chinese Foreign Ministry Spokesperson Lin Jian stated at a press conference:
“This is a crude interference in China’s internal affairs.”
“These malicious remarks must be immediately withdrawn; otherwise, Japan shall bear all consequences.”
“The remarks gravely violate the ‘One China’ principle,” and “challenge China’s core interests and infringe upon its sovereignty.”
“China firmly opposes this and will never tolerate it.” [3]

As is always the case, these are a barrage of overbearing and intimidating statements that show not the slightest respect or consideration for the prime minister of Japan, the highest political leader of a neighboring country.

Historical background

So, what exactly is the “One China” principle that Beijing asserts? Can the Taiwan issue truly be called “China’s internal affair”? I would like to trace the historical background once again.

The fundamental document governing relations between Tokyo and Beijing has been the Japan-China Joint Communique issued at the time of the normalization of bilateral diplomatic relations in 1972. Its third paragraph stipulates the following: [4]
“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.”

What China insisted on during the normalization of diplomatic ties was its position that “Taiwan is an inalienable part of the territory of the People’s Republic of China.” However, Japan neither agreed to nor accepted this position. That is precisely why, unlike other paragraphs written in a form indicating “mutual agreement,” the third paragraph ultimately took the form of presenting both sides’ respective positions side by side.

Then, why was Japan unable to agree? There were both legal and political reasons for this. [5]

Legally, Japan had already renounced its sovereignty over Taiwan under the San Francisco Peace Treaty, which came into effect in 1952. Japan therefore adopted a reserved position: “The question of where Taiwan, renounced under the San Francisco Peace Treaty, should belong is a matter to be decided primarily by the Allied Powers, and Japan is not in a position to make any statement on it.”

The above-mentioned phrase “fully understands and respects” goes further than the wording used in the Shanghai Communique between the United States and China—namely “acknowledge.” However, China was not satisfied only with this formulation. In the end, agreement was reportedly reached by adding the wording, “and maintains its stand under Article 8 of the Potsdam Declaration.” [6]

Article 8 of the Potsdam Declaration states that “the terms of the Cairo Declaration shall be carried out,” and the Cairo Declaration provides that “all the territories Japan has stolen from the Chinese, such as Manchuria, Formosa, and the Pescadores, shall be restored to the Republic of China.” By adding this clause, Japan allowed China to interpret the statement as Japan recognizing “the return of Taiwan to the Republic of China.” From Japan’s perspective, however, it is possible to explain that this merely reiterated the Potsdam Declaration, which Japan had already accepted.

More fundamentally, there was the concern that if Japan were to plainly acknowledge China’s claim that Taiwan is an inalienable part of Chinese territory, it would amount to recognizing the legitimacy of China’s position that it holds the ultimate right to liberate Taiwan by force. [7]

Another factor was political considerations involving the United States. A major diplomatic priority for the Japanese government in 1972 was the reversion of sovereignty over Okinawa. The United States was greatly concerned that, once Okinawa was returned to Japan, it might no longer be able to use the bases there as freely as it had under U.S. administration. More specifically, it was Washington’s desire that it wanted to ensure that no restrictions would arise on the use of U.S. bases in Okinawa in the event of situations such as a North Korean armed attack or China’s use of force to unify Taiwan.

In response to this, the Sato-Nixon Joint Statement of November 1969 noted that “the President referred to the treaty obligations of his country toward the Republic of China which the United States would uphold,” while Prime Minister Sato expressed his view that “the maintenance of peace and security in the Taiwan area is also a most important factor for the security of Japan.” It was precisely this political context that formed the background for settling on the wording “fully understands and respects.” [8] Japan could not agree to anything that might undermine the US position of defending Taiwan, which belonged to the free world.

It is for this reason that the Japanese government’s unified view expressed by Foreign Minister Ohira during the 1973 House of Representatives Budget Committee session is of particular significance—especially the phrase “basically” as mentioned in his view: “We consider the issue of confrontation between the People’s Republic of China and Taiwan to be, basically, a domestic issue of China.” The inclusion of “basically” conveys an important nuance. [9]

Takakazu Kuriyama, a career diplomat responsible for treaties at the Foreign Ministry then, made this point explicitly by going as far as to say: “The Taiwan issue is something that should be resolved through dialogue between the two parties across the Taiwan Strait, and the Japanese government has no intention of intervening in any way...(omitted)...However, if China were, even in the most unlikely scenario, to resort to the use of force to unify Taiwan (or what is called “liberation by force”), then this could no longer be considered a domestic matter. That is the meaning of the phrase basically.” His observation is one that we should continue to keep firmly in mind today.

Contemporary significance

As is clear from the above, the so-called “One China” principle is Beijing’s own unilateral claim, and the Japanese government has never stated that it accepts it. In fact, Japan has carefully chosen its wording precisely to avoid giving any recognition to China’s “unification by force.”

However, under the Xi Jinping administration, China has repeatedly made clear its stance of never hesitating to resort to the use of force. The long-assumed commitment to a peaceful resolution of the Taiwan issue has effectively disappeared as China’s military power has grown, and a voracious desire to challenge the status quo has come to the forefront.

More than half a century has passed since the normalization of diplomatic relations between Japan and China in 1972. During this time, predictions by some that a rising China would eventually absorb Taiwan have proven entirely mistaken. Taiwan has become recognized by the international community as a solid democracy with a population of roughly 23 million, and it has built indispensable supply chains—vital to the global economy—in critical sectors such as semiconductors. By contrast, the Chinese Communist Party’s “wolf-warrior diplomacy” has placed it far from winning over the minds and hearts of the Taiwanese people.

With China’s voracious drive to challenge the status quo now laid bare, the situation has clearly shifted from what it was at the time of diplomatic normalization half a century ago. Just like the old slogan of “Japan-China friendship,” has not the phrase “fully understands and respects” also reached the end of its shelf life?

If China were to resort to the use of force against Taiwan by for example attacking Kinmen or Matsu, “One China” they have insisted on could lose support from the international community and end up as castles in the air.

We are entering a period in which we cannot take our eyes off the Taiwan issue.