Days after Japan’s prime minister and China’s leader promised a new era of co-operation at a leadership summit, blunt comments from Sanae Takaichi about Taiwan and a threatening Chinese rejoinder have plunged relations between the countries into turmoil.
The row has deepened concerns about the relationship between the region’s two biggest economies, diplomats and academics said, at a time when US President Donald Trump’s transactional approach to trade and diplomacy has shaken up geopolitics.
The relationship between Japan and China, two regional heavyweights, is one of the most delicate in the world, said a senior adviser to three former Japanese prime ministers.
“Every change of leader, outside shock or change of the underlying situation, puts that balance at risk,” the person said.
Since the hawkish Takaichi won the leadership of Japan’s ruling Liberal Democratic party last month, Beijing has been on high alert for signs she will emulate her mentor, the late nationalist prime minister Shinzo Abe, in taking a tough line on China.
Tokyo, meanwhile, has been more openly warning of the most severe security environment in the region since the second world war in response to Beijing’s increasing assertiveness.
President Xi Jinping broke with tradition when he did not send Takaichi a congratulatory message on her election as prime minister.
Despite that initial snub, Japanese officials pushed hard for a meeting with Xi, according to people familiar with negotiations. That meeting took place at the Asia-Pacific Economic Conference in South Korea on October 31 and passed neutrally.
But a day later, Takaichi met Taiwan’s representative at the Apec forum, and posted a picture of the encounter on social media — both actions that drew immediate protest from China.
Takaichi then referred in parliament to a hypothetical situation in which a Chinese attack on Taiwan could be interpreted as an “existential threat” to Japan, that would allow Japanese Self Defence Forces to respond militarily.
The explicitness of Takaichi’s remark went further than any sitting Japanese prime minister has in the past, by implying that Tokyo could take military action without being attacked itself.
The comments sparked protest from Beijing, where a foreign ministry spokesperson vowed that “China will ultimately be reunified” and added that the country would “decisively crush any schemes to interfere with or obstruct China’s reunification efforts”.
China claims sovereignty over Taiwan and has threatened the use of military force if Taipei resists its control indefinitely.
China’s consul general in Osaka followed with a threatening post on X, saying that if a “filthy neck sticks itself in uninvited, we will cut it off without a moment’s hesitation. Are you prepared for that?”
Takaichi has refused to withdraw her remarks, though she indicated in parliament this week that she would not repeat them.
But her statements reflected the view of many in Japan’s defence and economic security ministries, according to people close to her cabinet.
Trump’s visit to the region last month may have emboldened Beijing and Tokyo to harden their stances, said Margarita Estévez-Abe, a political scientist at the Maxwell School of Syracuse University, leaving Japan flush with the success of Trump’s visit and China feeling victorious after securing a trade deal with Washington, she said.
“Takaichi feels she can speak her mind more strongly; China would have been more cautious if it had not come to an agreement with the US on tariffs,” said Estévez-Abe. “The chessboard has shifted quite a lot in the last 10 days. Both sides are emboldened.”
Nationalist Chinese commentator Hu Xijin slammed Takaichi as “reckless” and warned that she would try to “create more excuses for Japan to increase its military budget” and strain the limits of Japan’s pacifist constitution.
Takaichi has also been ambiguous about whether she would visit the controversial Yasukuni war shrine in Tokyo as prime minister. Abe’s visit to the shrine in 2013 drew fierce diplomatic protests from Beijing and warnings from US officials.
But Stephen Nagy, an international relations expert at the International Christian University in Tokyo, said that Takaichi’s background as economic security minister — in contrast with her predecessors — gave her an understanding of Japan’s vulnerabilities that would be at the core of her approach towards China.
“Takaichi has thought a lot more about economic security than Japanese prime ministers [Shigeru] Ishiba and [Fumio] Kishida. She thinks about resilience and she is going to make that her diplomatic brand,” said Nagy.
The prime minister’s focus on the domestic economy would starkly highlight Japan’s heavy reliance on Chinese manufacturing and the Chinese market as a driver of its own economic strength, said Hotaka Machida, a former Japanese diplomat now at the Institute of Geoeconomics think-tank.
That relationship would always be offset, however, by the security risk from Beijing and Tokyo’s dependence on the US as its “only option” as a defence guarantor.
“The current Japan-China situation is severe because China is a competitor and a challenger,” said Machida. “Japan is very concerned about China growing more militarily confident.”
One major complication for Japan’s stance towards China is the Trump administration, which has damaged the US’s image as a dependable military and economic backer, said Robert Dujarric, director at the Institute of Contemporary Asian Studies at Temple University in Tokyo.
Among Japanese officials, he added, “there is a new fear” of the harm that Trump could inflict on the US-Japan relationship.
“Takaichi may have the same policies as her predecessors and [China] has the same leader, but the cards that Takaichi and Xi are holding now are very different,” he said.
