When Japan’s newly promoted Prime Minister Sanae Takaichi, the nation’s first female leader, first met with Chinese President Xi Jinping, she said she wanted to pursue a “mutually beneficial” relationship as well as to “deepen their personal ties.”“As Japan and China are important partners, the long-term, stable and healthy development of bilateral ties aligns with the common expectations of both our peoples as well as the international community,” Xi said.[time-brightcove not-tgx=”true”]But just two weeks later, the neighboring countries have fallen into a diplomatic spat that neither side seems eager to climb out from.In Nov. 7 parliamentary remarks, Takaichi appeared to veer from Japan’s policy of “strategic ambiguity” towards the self-governed island of Taiwan, suggesting that an attack on Taiwan could amount to a “survival-threatening situation” that would permit Japan to exercise collective self-defense. Read More: Taiwan in the Shadow of WarHer remarks drew ire from China, which claims Taiwan as part of its territory and maintains its right to take control of it one day, including by force. Facing criticisms and warnings from Beijing, Takaichi, who is widely seen as a China hawk, has refused to retract her remarks, although she noted they were “hypothetical” and that she would refrain from making similar comments in future.China has now turned to wield the power of its citizens’ wallets to ramp up pressure on Japan. China’s embassy in Japan issued a travel advisory for Japan to its citizens, after which three Chinese airlines—Air China, China Southern, and China Eastern—offered passengers full refunds or free changes to Japan itineraries till the end of the year.“Recently, Japanese leaders have openly made explicit provocative remarks regarding Taiwan, severely worsening the atmosphere for exchanges between Chinese and Japanese people and posing significant risks to the personal and life safety of Chinese citizens in Japan,” China’s embassy in Japan said in a statement. “The Ministry of Culture and Tourism solemnly reminds Chinese tourists to avoid traveling to Japan in the near future.”If Chinese citizens take the travel warning into account, it could have a sizable impact on Japan’s economy. According to data from Japan Tourism Statistics, nearly 7.5 million people from mainland China visited Japan in the first nine months of this year, which made up almost a quarter of all foreign tourists.Beijing’s travel advisory also noted that xenophobic sentiments and incidents in Japan have risen this year, including attacks on Chinese citizens. The Chinese Ministry of Education issued a warning of increased risks to Chinese students planning to study in Japan on Sunday, according to state broadcaster CCTV.The spat threatens to upend already strained relations between Japan and China, and suggests that Takaichi is willing to take a more assertive position towards China than her predecessors. The Japanese premier, who assumed her role last month, has backed a Japanese military build-up in order to counter that of China, especially amid an ongoing dispute between the countries over contested territory in the East China Sea.Japan does not have official diplomatic ties with Taiwan and does not officially recognize Taiwan as a country. Instead, like the U.S., it maintains a policy of unofficial, working-level relations with Taiwan and has reiterated its position favoring a peaceful resolution to the China-Taiwan situation.The dispute “reveals that Beijing cannot let go of Taiwan at all, as the political legitimacy of the Communist Party of China is so tied to the Taiwan issue,” Ryu Yongwook, an assistant professor at the Lee Kuan Yew School of Public Policy in Singapore specializing in East Asian international relations, tells TIME.And Beijing may see this as an important moment to reaffirm its red lines.“Whenever China hears statements about Taiwan from external actors in an unfavorable light, particularly concerning tensions or potential contingencies, it responds quickly and assertively, regardless of the diplomatic signals those actors intend to send,” says Kei Koga, an associate professor at Singapore-based Nanyang Technological University’s Public Policy and Global Affairs Program.“Because she is early in her tenure and because her position is not quite stable yet, China sees itself as able to more fully test the boundaries,” Dylan Loh, another associate professor at Nanyang Technological University, told Bloomberg. “But by no means are the reactions in Beijing inauthentic, quite the contrary.”“This is about setting the terms early in Takaichi’s term, deterring other countries from similar rhetoric, and discouraging Tokyo from taking further steps,” Bloomberg Economics’ Jennifer Welch added.Here’s what to know about the diplomatic row, and what it means for China, Japan, and Taiwan.Takaichi strays from ‘strategic ambiguity’If there is an emergency in Taiwan involving “battleships and the use of force, then that could constitute a situation threatening the survival [of Japan], any way you slice it,” Takaichi said in parliament. Framing an attack on Taiwan as an “existential threat” would potentially allow Japan to respond with force under the country’s 2015 security legislation.Takaichi has refused to retract her remarks, calling them “consistent with the government’s traditional position.”It is perhaps the clearest and most forceful view toward the China-Taiwan situation since that of Takaichi’s mentor, the late former Prime Minister Shinzo Abe. “A Taiwan emergency is a Japanese emergency, and therefore an emergency for the Japan-U.S. alliance,” Abe said in 2021, implying that a Chinese attack on Taiwan could draw a response from Japan. Former Prime Minister Shigeru Ishiba, Takaichi’s direct predecessor also of the same party, on the other hand, noted on Thursday that previous administrations consistently avoided making such a definitive statement on Taiwan, according to Chinese state media.China’s embassy in Japan said on Monday that Takaichi’s remarks “mark the first instance of a postwar Japanese Prime Minister linking the Taiwan issue with the ‘national crisis situation,’ and the first time proposing that Japan may intervene militarily in the Taiwan Strait.” The embassy suggested such a view is akin to “the tactics used by Japanese militarism in history to launch invasions under the pretext of a ‘national crisis.’”“Japan has historically avoided explicit statements on such scenarios because they are hypothetical and could provoke other states, particularly China,” says Koga. Still, in effect, he adds, Takaichi’s remarks do “not significantly deviate from Japan’s basic posture toward Taiwan” nor do they indicate a “shift in policy” but rather were regarding a possible “contingency involving military attacks on Taiwan or U.S. action to break a naval blockade” and whether that situation would be an existential threat to Japan.“Although Japan’s basic stance remains unchanged, China has interpreted Takaichi’s remarks as a rhetorical or diplomatic shift, possibly policy shift,” says Koga. “As long as China continues to frame them this way, it will be difficult for Japan and China to reconcile their views on this issue.”Whether or not Japan should come to Taiwan’s defence in the event of an attack by China, in the name of collective self-defense, is a question that has divided the Japanese public. A Kyodo news agency poll published on Sunday found that 48.8% of respondents were in favor of Japan doing so while 44.2% were against it. At the same time, 60.4% of respondents supported Takaichi’s plan to increase Japan’s defense spending.Takaichi’s remarks “crystallized what many suspected was Japan’s security policy on Taiwan—that is, that Tokyo regards a military conflict in the Taiwan Strait as an existential threat to Japan” says Ryu. “It is clear public support for Taiwan and a slap in the face for China.”China reacts stronglyTakaichi’s remarks prompted a fiery response from China. China’s Vice Foreign Minister Sun Weidong summoned Japan’s ambassador to Beijing on Thursday to address the comments, marking the first time that Beijing has called in a Japanese ambassador in over two years.“Those who play with fire will burn themselves; the serious consequences arising from this will be borne by the Japanese side itself,” China’s embassy in Japan said on Monday.Koga says this spat could prompt China to ramp up its regional militarization.“On the security front, China may use this episode as justification to increase its presence and monitor Japan’s activities near the Taiwan Strait, while continuing to issue travel advisories,” he says. Over the weekend, four armed Chinese Coast Guard ships sailed through the disputed waters of the Senkaku Islands (called Diaoyu Islands in China), which are controlled by Japan. The Chinese Coast Guard said it was part of a lawful “rights enforcement patrol” operation.“Beijing will feel that it has to demonstrate a sufficiently strong public display of ‘hurting’ Japan, to satisfy the Chinese domestic public,” says Ryu, adding that the Chinese public could also launch a boycott of Japanese goods as it did in 2012 after Japan nationalized the disputed islands.At the same time, China’s Foreign Ministry spokesperson Lin Jian on Friday expressed concerns about Japan’s apparent ambiguity over its non-nuclear principles, calling Japan’s openness to possessing nuclear powered submarines “a negative policy shift, which sends a dangerous signal to the international community.”Recalling Takaichi’s remarks, Lin said, “Owing to these moves by Japan, its neighboring countries in Asia and the international community have to strongly call into question and worry about: Has Japan truly made a clean break with militarism?”The diplomatic row has appeared to re-stoke tensions between China and Japan, which have long been fragile given that many in China do not see Japan as having repented for its wartime abuse, although relations had been warming this year after China recently partially lifted a ban on Japanese seafood imports.Chinese state media has published a number of articles criticizing Japan, with one calling Takaichi’s remarks “extremely sinister” and the “first threat of force” against China in 80 years. Another commentary argued that the remarks were not “isolated” but are part of a wider revival of Japanese militarism. “From her repeated visits to the Yasukuni Shrine, to the denial of the historical reality of the Nanjing Massacre, and the promotion of the ‘China threat’ narrative, her actions mirror the troubling path of Japan’s past militarism,” the article read. “These actions constitute an effort to whitewash Japan’s history of aggression and honor militarist figures.”An account linked to China’s state broadcaster also said in a social media post on Saturday that Beijing is prepared to take substantial countermeasures against Japan, signalling that China is not backing off.“Should the Japanese side fail to draw lessons from history and dare to take a risk, or even use force to interfere in the Taiwan question, it will only suffer a crushing defeat against the steel-willed People’s Liberation Army and pay a heavy price,” Chinese Defence Ministry spokesperson Jiang Bin said in a statement.China’s consul general in Osaka Xue Jian also made a since-deleted post on X that said, “We have no choice but to cut off that dirty neck that has been lunged at us.” The post drew criticism from Japan, and Vice Foreign Minister Takehiro Funakoshi summoned Chinese ambassador to Japan Wu Jianghao over the post.Japan has urged China to moderate its response, with Japan’s Chief Cabinet Secretary Minoru Kihara calling on China to take only “appropriate measures,” Kyodo reported on Saturday. “China’s view is not in line with Japan’s understanding. It is precisely because differences remain that multilayered communication between Japan and China is essential,” Kihara said.“These announcements that hinder bilateral exchanges diverge from the broader direction agreed by our respective leaders to build constructive and stable ties in line with a strategic and mutually beneficial relationship,” Japan’s Chief Cabinet Secretary Minoru Kihara said on Monday, according to Japanese public broadcaster NHK. “It is not something we can accept.”