Japan-Taiwan Relations Enter ‘Deep Waters.’ Will They Sink or Swim?

In the wake of the August 10 incident in Nagasaki, where Taiwan’s representative Lee Yi‑yang declined to attend the atomic‑bombing memorial after being seated outside the diplomatic zone, the paradox of Japan‑Taiwan relations has become starkly visible. The episode, reported by The Diplomat, underscored how economic and technological interdependence now collides with long‑standing diplomatic constraints rooted in Japan’s “One China” policy, itself anchored in the 1972 Japan‑China Joint Communiqué. As scholars of Korean and broader Northeast Asian diplomacy note, such tensions echo the delicate balancing acts that Seoul has long performed in its own relations with Beijing and Washington.

Historical Foundations of the “One China” Constraint

The 1972 Joint Communiqué, in which Japan pledged to “fully understand and respect” the People’s Republic of China’s claim that Taiwan is an inalienable part of Chinese territory, has become the cornerstone of Tokyo’s diplomatic posture. Although Japan never formally recognized Chinese sovereignty over Taiwan, the communiqué nonetheless frames Beijing’s recurring objections whenever Japan appears to move beyond a strictly unofficial relationship. This historical backdrop explains why Nagasaki officials framed the seating arrangement as a routine reflection of Japan’s longstanding policy rather than a targeted slight.

For Korean analysts, the Japanese experience offers a comparative lens: South Korea’s own “Three‑No” policy toward North Korea—no recognition, no diplomatic relations, no military alliance—has similarly limited Seoul’s ability to deepen ties with a neighboring state despite shared economic interests. In both cases, historical treaties and diplomatic conventions constrain contemporary strategic choices.

Economic Integration: The TSMC Kumamoto Project

The most visible manifestation of deepening Japan‑Taiwan cooperation is Taiwan Semiconductor Manufacturing Company’s (TSMC) investment in Kumamoto. Initiated as a commercial venture, the project has evolved into a strategic pillar for East Asian supply‑chain resilience. By linking Taiwan’s manufacturing leadership with Japan’s expertise in semiconductor equipment, specialty chemicals, advanced materials, and precision machinery, the Kumamoto plant diversifies production geography and reduces reliance on any single national hub.

Beyond the factory floor, the Kumamoto initiative has sparked a cascade of partnerships across Kyushu. Local governments, universities, research institutes, and businesses have launched joint research programs, workforce‑training schemes, and student exchanges. These collaborations illustrate how a single corporate investment can become a platform for broader regional integration, echoing Korean models where chaebol‑led projects often seed university‑industry consortia that feed national innovation systems.

Expanding Technological Cooperation

While semiconductors remain the flagship sector, Japan and Taiwan are increasingly collaborating in artificial intelligence, cybersecurity, drone technology, digital governance, and economic security. The 2025 Japan‑Taiwan Digital Trade Agreement, cited in the source material, formalized many of these emerging linkages, signaling a shift from purely commercial exchanges to joint development of strategic capabilities.

This convergence mirrors Korea’s own trajectory, where the Ministry of Science and ICT (MSIT) has partnered with private firms to create “digital corridors” that link domestic innovation with overseas ecosystems. In both Japan‑Taiwan and Korea‑U.S. contexts, technology is no longer a peripheral trade item but a core component of national competitiveness and strategic resilience.

Institutional Gaps and the Need for Robust Frameworks

Despite the proliferation of practical agreements—ranging from fisheries and taxation to railway cooperation and plant‑variety certification—the institutional architecture of Japan‑Taiwan relations remains fragmented. Most recent accords are narrowly technical, lacking the comprehensive scope that would anchor the deepening economic and security ties.

Analysts at think tanks such as the Asan Institute and KDI have long warned that without a robust, high‑level framework, cooperation risks remaining ad‑hoc and vulnerable to political push‑backs. The ongoing debate over a bilateral Economic Partnership Agreement (EPA) exemplifies this tension: Taiwan repeatedly urges a comprehensive EPA to solidify trade and investment flows, while Tokyo remains hesitant, mindful of Beijing’s potential reaction.

Geopolitical Constraints: Beijing’s Leverage

Beijing’s strategic calculus, anchored in the 1972 communiqué, consistently seeks to limit Japan’s engagement with Taiwan whenever Tokyo appears to cross informal red lines. The Nagasaki seating controversy is a microcosm of this broader pattern: any move that could be interpreted as an upgrade in official relations invites Chinese criticism, which in turn pressures Japan to calibrate its diplomatic gestures.

This dynamic is not unique to Japan. Seoul’s own security environment is shaped by the “one‑China” narrative, as well as by North Korea’s provocations, compelling South Korean policymakers to balance economic incentives with geopolitical sensitivities. The Korean experience underscores how regional powers must navigate overlapping spheres of influence while pursuing national interests.

Societal Exchanges and Public Perception

Beyond high‑level policy, people‑to‑people ties between Japan and Taiwan have reached unprecedented levels. Educational exchanges, cultural festivals, and tourism flows have created a shared sense of affinity, often compared to the historic “friendship” narratives that underpin Korea‑Japan civil‑society interactions despite lingering historical disputes.

These societal bonds serve as a stabilizing factor, providing a reservoir of goodwill that can sustain cooperation even when official channels are constrained. As scholars note, such “soft power” linkages can gradually expand the policy space, offering a buffer against abrupt diplomatic setbacks.

Future Trajectories: Toward a Sustainable Partnership

Looking ahead, the challenge for Japan and Taiwan is to translate their deepening convergence into a sustainable partnership that can weather Beijing’s objections. This will likely require the development of stronger institutional mechanisms—perhaps a revised EPA or a multilateral framework that includes third‑party guarantors—to institutionalize cooperation while diffusing bilateral sensitivities.

For Korean policymakers and scholars, the Japan‑Taiwan case offers a valuable comparative lesson: the need to align economic imperatives with strategic foresight, leveraging both technical agreements and broader societal engagement to build resilience. As the regional security environment evolves, the capacity of Japan and Taiwan to navigate the “deep waters” of their relationship will hinge on their ability to balance pragmatic interdependence with the diplomatic realities imposed by a powerful neighbor.

This article was produced with AI-assisted research and editorial support. Reporting is based on the source material cited below. Sources: The Diplomat; thediplomat.com; Global1.News (01 November 2026).

By Prof. David Park, Staff Writer