The Senkaku Islands (©Sankei by Kenji Suzuki）
The Qing dynasty's (1644-1912) geographical gazetteer, Da-Qing yitong zhi (Qianlong Edition), describes Taiwan as "belonging to Japan" and as a "remote frontier historically unconnected to China."
Taiwan was likewise not regarded as part of China before the Qing era. The preceding Ming Dynasty sources consistently treated the island as "external to the empire."
In The History of the Ming, for instance, Taiwan is classified as a "foreign territory." Meanwhile, Da Ming yitong zhi, in its section on Foreign Barbarians, describes Taiwan as an affiliated island of the Ryukyu Kingdom.
Taiwan came under Qing rule only after it was conquered in 1683, when Admiral Shi Lang defeated Ming loyalists who had used the island as a base of resistance. The Qing court then established the Taiwan Prefecture in the same year, during the Kangxi reign.
This history echoes contemporary Beijing's insistence that Taiwan is "an inalienable part of China's territory," and its preparedness to exert that claim by force.
Taiwan and Strategic Ambiguity
Following the collapse of the Qing dynasty in 1912, the Republic of China (ROC) was established on the Chinese mainland. And after its defeat in the Chinese Civil War, the ROC government retreated to Taiwan in 1949.
Beijing's claim that Taiwan is its inalienable territory and a core interest draws directly on the Qing dynasty's effort to subdue the last remnants of Ming rule.
Notwithstanding, in the 1972 Japan–China Joint Communiqué, the Japanese government stated that it "fully understands and respects" China's position that Taiwan is an inalienable part of its territory.
In doing so, Tokyo adopted a deliberately ambiguous stance on Taiwan similar to that of the United States.
Striking China's Achilles' Heel
On November 7, 2025, during a budget committee session, Prime Minister Sanae Takaichi responded to a question from opposition lawmaker Katsuya Okada, saying, "If a [Taiwan contingency] involves the use of battleships and the exercise of military force, it could undoubtedly be considered a survival-threatening situation for Japan."
The remarks triggered a sharp reaction from Xue Jian, China's consul general in Osaka. He posted on social media that he would "cut off that dirty head that dared to butt in without a moment's hesitation." Rapid deterioration in Tokyo–Beijing relations soon ensued.
But the groundwork for this tension had already been laid on October 31 at the Japan–China summit in Gyeongju, South Korea.
At the meeting, Takaichi conveyed serious concerns regarding Beijing's actions in the South China Sea, as well as the situations in Hong Kong and the Xinjiang Uyghur Autonomous Region. Her remarks struck at the Achilles' heel of the Xi Jinping administration.
Since its founding, the People's Republic of China, drawing on precedents established by earlier dynasties, has asserted control over East Turkestan (Xinjiang Uyghur Autonomous Region), Tibet (Tibet Autonomous Region), and Inner Mongolia.
Xi was therefore wary of Takaichi's remarks that touched on a very sensitive part of Chinese history.
When Taiwan Becomes a Japan Issue
The Xi administration insists that "resolving the Taiwan issue and achieving the complete reunification of the motherland is the Party's unwavering historical mission."
Against this backdrop, Takaichi's Taiwan-related remarks were likely perceived in Beijing as external interference with Xi's goal of "great rejuvenation of the Chinese nation."
However, if China were to invade Taiwan and a contingency were to erupt, vital shipping routes would be disrupted. The damage would extend well beyond the Japanese economy.
Since 1971, China has claimed to regard the Senkaku Islands as part of Taiwan and has steadily plotted their seizure.
China also intensified its moves in the South China Sea following the 2010 collision between a Chinese fishing vessel and a Japan Coast Guard patrol ship. It began occupying parts of the Spratly Islands, justifying its actions with Republic of China–era materials such as the Map of the South China Sea Islands.
Given these realities, a Taiwan contingency is inseparable from a Japan contingency.
Beijing's Narrative Backfires
In fact, the Spratly Islands were claimed by Japan in 1939 and designated the New Southern Islands. They remained under Japanese control until Japan renounced its claims in the 1951 Treaty of San Francisco.
On December 2, 2025, the Chinese Embassy in Japan suddenly posted on X that the Treaty of San Francisco was "illegal and invalid."
It sent shockwaves through both Taiwan and Japan. This is because invalidating the San Francisco Treaty would call into question the postwar disposition of territories Japan renounced, including Taiwan and the Spratly Islands.
In retrospect, the current Chinese government's flustered reaction recalls the situation in 2005, when Shimane Prefecture enacted its Takeshima Day ordinance.
At the time, the Junichiro Koizumi administration sought to block the move to avoid heightening tensions with South Korea. But the prefectural assembly proceeded nonetheless.
Responding to the ordinance, the South Korean government, long committed to "quiet diplomacy" over the Takeshima issue, effectively acknowledged the existence of a territorial dispute by treating it as a matter that transcended Japan–South Korea relations.
Takaichi Must Remain Adamant
When national sovereignty is violated, its restoration is a fundamental duty of government. To that end, Prime Minister Takaichi's remarks were entirely natural.
It was the Chinese government, shaped by a pattern of wolf warrior diplomacy and economic coercion, that reacted with visible disarray.
Since her remarks, Chinese Coast Guard vessels have markedly increased their provocative activities in waters surrounding the Senkaku Islands. And those intimidations are premised on the threat of invasion.
As Shimane Prefecture's example demonstrates, restraint is unnecessary when defending national sovereignty. Once a Taiwan contingency becomes a Japan contingency, it necessarily will encompass Japan's Senkakus.
RELATED:
- As the New Year Begins, Stay Attentive to the Dangers of a Taiwan Emergency
- Senkaku Islands See Surge in Chinese Patrols and Research Ships
- Expert: Why A Taiwan Contingency Won't Stay Just an Internal Matter
Author: Masao Shimojo, The Sankei Shimbun
(Read this in Japanese)
