Trump’s return drives closer cooperation in East Asia
The Trilateral Cooperation Secretariat (TCS) operates quietly beneath the global radar despite an escalating trade war and unpredictable diplomacy shaped by US politics. This Seoul-based organisation, established by China, Japan and South Korea in 2011, is gaining significance amid geopolitical shifts following US President Donald Trump’s disruptive return to office. Symbolically, the TCS has come to embody a modest yet notable effort at trust-building among the three historical rivals.
At a ministerial meeting held at the end of March 2025, the three governments agreed to extend the tenure of the TCS secretary-general and deputy secretaries from two to three years. While seemingly a minor administrative adjustment, the decision reflects a cautious move towards institutional continuity. It symbolises a measured level of newfound comfort and growing mutual trust among nations that have historically approached one another with caution. Shin Bong-kil, the first secretary-general of the TCS, had previously noted that this cautiousness was exemplified by the organisation’s rotating secretary-general system with short two-year terms.
China’s Foreign Minister Wang Yi explicitly acknowledged that the extension represents a full endorsement of the TCS’s role. This demonstrates confidence that the organisation can play a meaningful part in deepening cooperation in East Asia amid growing global uncertainty. But this endorsement should not be overstated — the TCS does not address core regional disputes such as territorial claims, historical grievances or maritime boundary demarcations. It remains a technical forum with limited capacity to resolve high-stakes geopolitical conflicts.
Yet, Trump’s overtly protectionist stance and transactional diplomacy have pushed allies and adversaries closer together. Still, this convergence should be understood as reactive rather than transformative. Countries like Vietnam, which have traditionally been cautious of China, continue to hedge carefully between Beijing and Washington. The European Union is following a similar path.
Shared concerns over US unpredictability drive this shift. Trump’s reciprocal tariffs and disregard for longstanding alliances have unsettled traditional US partners in Asia.
Moon Chung-in, a prominent South Korean political scientist, urged South Korea to prepare for a future without the United States or US troops. This sentiment echoes how Europe, too, is bracing for a future without the United States. While provocative, such a view is likely to remain at the margins of mainstream policy discourse in both Seoul and Tokyo unless structural obstacles are meaningfully addressed.
Rather than a strategic realignment, the increased activity around the TCS reflects short-term adjustments to economic and security uncertainty. As TCS Chief Lee Hee-sup remarked in March 2025, China, Japan and South Korea have historically ‘turned crises into opportunities’.
Trade and commerce ministers of the three countries met in Seoul for the first trilateral trade talks in over five years in March 2025, agreeing to accelerate long-stalled negotiations toward a free trade agreement to address ‘emerging challenges’.
Japan has publicly described the ministerial meeting as taking place at a ‘turning point in history’. This phrasing does not read as mere diplomatic rhetoric — it reflects the seriousness with which Tokyo views the evolving trilateral relationship.
Japan has traditionally balanced its security alliance with the United States against deep economic ties with China. It appears to have shifted towards seeing institutionalised cooperation as increasingly vital to long-term regional stability. Japanese Foreign Minister Takeshi Iwaya has stated that promoting ‘future-oriented’ cooperation between the three countries is crucial for guiding the region from ‘division to coordination’. At the same time, Japan has resisted capitulating to the United States’ tariff pressures, signalling a cautious assertion of its economic autonomy.
Geopolitical disruptions have also prompted Seoul to recalibrate the stance it held under the conservative, pro-US government of former president Yoon Suk-yeol. The Yoon administration’s policies were characterised by dependence on the United States for both security and the economy. South Korea appears to be cautiously reverting to a dual dependency on China for economy and the United States for security.
East Asia’s geopolitical reality seems to be increasingly shaped by this return to dual dependency. As Lee eluded to in an interview in March 2025, economic cooperation among China, Japan and South Korea is indispensable, just as security cooperation among South Korea, Japan and the United States is essential. The United States remains essential for security, but China’s role as the region’s economic linchpin is undeniable. China is the largest trading partner for both Japan and South Korea.
High-level ministerial meetings in Tokyo and Seoul suggest that Japan and South Korea are reorienting their economic strategies by partnering with China. Together, they aim to restore the World Trade Organization’s central role in maintaining a rules-based multilateral trading system — a stance emphasised by South Korean Industry Minister Ahn Duk-geun. This trilateral cooperation aims to mitigate disruptions caused by US unpredictability and its ongoing trade war. The economic dialogue between the three countries underscores this dynamic. At the prospect of trade tensions in March, the three governments reportedly agreed to coordinate tariffs in response to US measures.
This measured institutionalisation through the TCS loosely echoes the early stages of the European Union, which began with functional cooperation and gradually expanded. But the differences are stark. The TCS lacks binding authority, economic integration or supranational ambition.
Its role is facilitative, not directive — symbolising minimal yet necessary trust-building among three neighbours with deeply entangled histories.
Such trust-building is crucial in an era shaped by uncertainty. The United States has, albeit indirectly, accelerated the trilateral cooperation that the TCS represents. The United States has also indirectly prompted tactical cooperation among China, Japan and South Korea, but it has not undone long-standing divisions that remain constrained by unresolved historical grievances, maritime disputes and enduring security dependencies. This has prompted China, Japan and South Korea to take the first step in strengthening regional frameworks within the multilateral trade system, potentially buffering against external disruptions.
The implications go beyond regional stability. They signal limited, interest-based coordination. They also seem to point to a broader shift towards a multipolar international order — one less dependent on US leadership and possibly, as UK Prime Minister Keir Starmer warned after Trump’s sweeping global tariffs, ‘the beginning of a new era’.
Ming Gao is Researcher of East Asia Studies in the Department of History at Lund University.