A warning from Japan’s prime minister about Taiwan has triggered a sharp exchange with Beijing, revealing how nationalism is reshaping diplomacy.

On 7 November 2025, Japanese Prime Minister Sanae Takaichi, facing questioning from an opposition lawmaker, told the Diet that if China were to deploy warships and use force against Taiwan, it could potentially lead to an ‘existential crisis’ for Japan. Under Japanese law, such a scenario would allow for a limited use of force. Her comments quickly triggered a heated war of words between Japan and China.

China’s Ministry of National Defence, Ministry of Foreign Affairs and state media condemned Japan for overestimating its capabilities and harbouring remilitarisation ambitions. But the criticism did not force Takaichi to back down or retract her remarks. Coupled with her meeting with Taiwanese representatives at the APEC summit a few weeks earlier, the episode has put relations between Japan and China under strain within the first month of Takaichi’s cabinet.

Takaichi’s remarks were not surprising. As a key inheritor of former Japanese prime minister Shinzo Abe’s security policy legacy, she has consistently supported amendments to Article Nine of the Japanese Constitution — which renounces the threat or use of force as means of settling international disputes — and a more proactive defence policy. Before becoming prime minister, she was also a strong advocate of Japan’s more active involvement in the Taiwan issue.

While her comments may be logical from a political standpoint, her strong remarks as a newly appointed prime minister still cast uncertainty over the future of Japanese diplomacy. They drew criticism from opposition leaders such as former prime minister Yoshihiko Noda, as well as former prime minister Shigeru Ishiba within the Liberal Democratic Party (LDP). But Takaichi’s comments were probably not a mere slip of the tongue. Rather, they seemed to reflect a degree of political calculation.

In July 2025, the LDP suffered an historic defeat in the House of Councillors election, losing its majority in both houses of parliament. This exposed conservative voter fatigue with the policies of the moderate right-wing party, with some supporters switching to more conservative parties, sounding alarm bells within the LDP. Three months later, with the resignation of Ishiba as prime minister and the withdrawal of long-time ally Komeito from the ruling coalition, LDP rule seemed to be facing a severe challenge.

Against this backdrop, Takaichi reached an agreement with the more conservative Japan Innovation Party and formed a ruling coalition. While this helped the LDP retain power, it also meant losing the moderating influence of a more centrist partner. For such a right-wing ruling coalition, regaining the favour of conservative voters became crucial to maintaining power. In this context, pointing the finger at China seemed like a surefire way to win over voters.

The view that China’s growing military power threatens Japan’s national security has become a consensus in Japanese society. Takaichi’s vision of Japan’s military intervention in a potential ‘Taiwan contingency’ necessitates a further strengthening of its military capabilities, creating more favourable conditions for constitutional amendments. This is clearly what conservative voters want to hear. A predictably strong response from China could also help Takaichi frame Japan’s neighbour as arrogant and ambitious.

Unsurprisingly, Takaichi’s remarks were embraced by nationalist discourse as a courageous act of resistance against Chinese hegemony and a demonstration of Japan’s determination to safeguard its national security. One poll showed an increase in support for the Takaichi administration after her comments. Opposition politicians who disagreed were portrayed in the media as cowardly and pro-China. In any case, Takaichi’s remarks helped her cabinet gain an initial foothold, albeit at the cost of relations with Japan’s neighbour.

Yet Takaichi’s remarks neither committed Japan to military intervention in the event of Chinese military action against Taiwan nor amounted to an effective deterrent. The reaction in China reflects not only rising anti-Japanese sentiment in recent years, but also a long-standing dismissive attitude towards Japan’s military power in Chinese public opinion.

Takaichi’s remarks were widely interpreted on Chinese social media as a provocation disproportionate to Japan’s actual capabilities, sparking online nationalist cheers for a potential military conflict between the two countries. This wave of nationalist sentiment is clearly useful for Beijing and provides an opportunity to project more assertive rhetoric — a common practice in Chinese diplomacy.

Xue Jian, China’s consul-general in Osaka, responded to Takaichi’s comments on X with the phrase ‘ cut off that dirty head’, emblematic of China’s ‘wolf warrior diplomacy’. He is known for his frequent posts on social media. Though sometimes considered overly radical, his four years in the position suggest that the Chinese government tacitly approves of his style. These radical anti-Japanese narratives, which permeate both public opinion and government rhetoric, are products of China’s nationalist discourse reproduction system.

In any case, the war of words between China and Japan triggered by Takaichi’s remarks is unlikely to escalate into military conflict, but it has clearly provided a tool for nationalists in both countries. For Japan, the Takaichi administration hopes to gain urgently needed public support for the LDP. Yet sacrificing stability in relations with China means the new cabinet will face even more severe diplomatic challenges, testing its ability to manage nationalist pressures in bilateral relations.

Republished from EAST ASIA FORUM on 8 December 2025.