It Starts with Taiwan, Where Will It End?

Sino-Japanese relations have once again taken center stage in East Asian geopolitics following a dramatic diplomatic spat in late 2025, marked by mutual warnings, economic retaliation, and heated rhetoric over Taiwan and historic grievances. The episode reflects not just the present tensions, but centuries of complicated history between the two nations—a history that continues to shape their interactions and, potentially, the balance of power in Asia.​

Turbulent Relationship

Sino-Japanese relations are inherently complex, rooted in historical animosities dating back to the late 19th and early 20th centuries. China and Japan fought several wars, the most infamous being the Second Sino-Japanese War (1937-1945), which left deep scars in Chinese memory due to Japanese military atrocities. Post World War II, Japan underwent a pacifist transformation under U.S. occupation, while China experienced revolutionary upheaval. Both countries emerged as regional powers in the following decades, but their political systems, strategic interests, and historical narratives often clashed.​

Normal diplomatic ties were restored in 1972. However, territorial disputes, most notably over the Senkaku/Diaoyu Islands, and persistent war memory issues have continually flared up, hindering deeper cooperation. This fraught history underpins today's mutual suspicion and rapid diplomatic escalations.

Taiwan in Focus

The present crisis was triggered by comments from the Japanese Prime Minister, Sanae Takaichi, in early November 2025. Takaichi suggested that a Chinese attack on Taiwan could prompt a Japanese military response, explicit rhetoric that breaks with Tokyo's prior strategic ambiguity regarding the self-ruled island—a stance long maintained to avoid antagonizing Beijing. China promptly condemned these remarks, labeling them a dangerous violation of the "One China" principle and a direct threat to the foundation of Sino-Japanese relations.​​

Beijing responded with a series of retaliatory measures, including suspending Japanese seafood imports, dealing a significant blow to Japanese exporters, issuing warnings to Chinese citizens about travel to Japan, citing safety concerns, sending Coast Guard patrols around disputed islands claimed by both nations, and stalling high-level meetings at the Group of 20 summit, underscoring the chilling effect on diplomacy.​

Both countries have issued advisories to their nationals, warning of increased risks and calling for vigilance. The spat swiftly spilled into economic and day-to-day affairs, underscoring the rapid escalation mechanism built into their relationship.​​

Historical Resonance

Neither China nor Japan operates in a vacuum. The 2025 confrontation draws on years of steadily rising Chinese military activity around Japan's southwestern islands and a shift in Japanese defense policy. According to Japan's July 2025 defense white paper, China is seen as "an unparalleled and the most formidable strategic challenge," with explicit warnings that a military emergency involving Taiwan would be viewed as a direct threat to Japan’s national survival.​

Japan's era of pacifism, once strongly rooted in the postwar constitution, has given way over the past decade to an expanded Self-Defense Force role and closer military cooperation with the United States. This has come amid growing anxieties over China's military modernization, its assertiveness in the East China Sea, and its ambitions around Taiwan.

China, under Xi Jinping's increasingly nationalistic and assertive rule, has pressed historical grievances, invoked memories of Japanese wartime aggression, and bolstered its capabilities around disputed territories. Whenever diplomatic crises flare, Beijing habitually reminds Tokyo to "repent for its history of aggression and earn the trust of its neighbors," even as its own power projection grows.​

Economic Interdependence vs. Political Competition

Despite these strategic and historic rivalries, China and Japan remain deeply economically intertwined. Japan, though outpaced by China's GDP, is still a major investor and trading partner. The Chinese travel boycott and seafood import suspension illustrate how economic levers remain Beijing's preferred tools of pressure, designed both for domestic effect and to unnerve Japan's policymakers.​

Japan, for its part, knows economic retaliation alone cannot shift the security environment. The nation's defense planners increasingly see China's rapid militarization as blurring the line between economic competition and outright strategic rivalry.​

Geopolitical Implications: Asia and Beyond

The current spat is more than a bilateral issue; its ramifications ripple across the region. The Taiwan question lies at the heart of U.S.-China strategic competition. Washington supports Japanese defense modernization as part of its alliance structure aimed at deterring China, and these latest Japanese statements reflect, in part, alignment with U.S. interests in resisting Chinese coercion.​

Other regional actors, like South Korea, find themselves in a diplomatic quandary, torn between economic ties to China and security partnerships with Japan and the U.S. The current standoff adds another layer of uncertainty to the Taiwan Strait, the East China Sea, and the broader Indo-Pacific, where even minor miscalculations could escalate tensions further.​

Toward a New Strategic Era

This latest episode marks a significant turning point in Sino-Japanese relations. The abandonment of ambiguity over Taiwan by Japanese leadership signals both rising resolve and higher stakes in the regional rivalry. China's robust response—combining economic, diplomatic, and military signals—demonstrates its determination to challenge what it perceives as encirclement and to punish what it calls "provocation" on the Taiwan issue.​​

For now, formal war remains unlikely, as both sides are wary of catastrophic escalation and the disruption of economic ties. Yet the old certainties—the insulation of economics from geopolitics, the predictability of strategic ambiguity, the taming effect of U.S. alliance leadership—are being tested as never before.

What occurs between China and Japan in the coming months will not only determine the course of their bilateral relations, but also profoundly shape the future of the Asian balance of power, global supply chains, and the prospects for peace—or confrontation—across the Taiwan Strait and beyond. The world will be watching how two of Asia’s giants navigate the dangers of the past and the challenges of today’s geopolitics