Written by Carlos Francisco Torres Morales.
Image credit: created by the author.
“–So, unlike Ukraine, to be clear, Sir: U.S. forces –U.S. men and women– would defend Taiwan in the event of a Chinese invasion? –Yes.” Although U.S. officials diluted assertive language suggesting unconditional security pledges, these remarks by President Biden in his 60 Minutes Interview became evidence for analysts that Washington had finally recalibrated its approach to Taiwan’s defence, given China’s intensified coercion, and skyrocketing Sino-American tensions that created a consensus on containing its ambitions.
Given its long-held views on Taiwan’s relevance in sustaining its alliances’ credibility, and re-estimating their value as an asymmetric advantage against Beijing’s rising capabilities, the U.S. pressures its allies to publicly align with Taipei and clarify their roles in a contingency. Japan and South Korea, probably its most capable allies in Asia, tightened security ties with Washington to balance against Chinese pressure; nonetheless, declaring unambiguously their solidarity exceeds what they are willing to do for Taiwan.
Using an alliance framework, this commentary argues that Tokyo and Seoul’s reluctance to publicly convey support to Taipei stems from strategic caution, since this could provoke the undesired effects, they would seek to deter by extending clear security assurances, but also to retain flexibility in redefining their stances vis-à-vis Taiwan (and China).
Hub-and-spoke and U.S. shifting perceptions on Taiwan.
To unravel the reasons for this caution, let us quickly reinstate some terms in alliance theory and the origins of the U.S. hub-and-spokes system, as the specific provisions included in the alliance contract inform allies’ assumptions of their role in crises outside its scope. Alliances are a phenomenon or the broad spectrum of alignments, as “…mutual expectations between two or more states that they will have each other’s support in disputes or wars with particular other states,” explicitly enshrining these pledges in a formally signed contract, and creating a structure to coordinate these expectations and preferences between allies.
This in turn creates a dilemma, since the actions that bring more security invite entrapment, but diminishing them risks abandonment. It is also possible for a state to fear entanglement in issues barely shared with its ally, or without the same intensity. Lastly, as the U.S. preferred response to a Taiwan contingency, coalitions need a mention: consisting of loose groupings of states that disband after meeting a common task, these rarely emerge automatically, whilst ideology and prior alliance ties are weak drivers in coalition-building. Rather, recruiters states must convince potential participants that an operation furthers their interests.
The U.S.’s alliance network in Asia, also known as hub-and-spokes for its design, originally comprised asymmetrical security partnerships centred on a patron, who holds strong bilateral ties with its clients in exchange for conformity. Multiple accounts exist over why it adopted this layout: Victor Cha’s powerplay theory is the most cited, arguing that Washington did this to control its allies’ foreign policies, but alternative explanations highlight allied preferences, asserting this better satisfied their specific security needs.
Therefore, Washington served as the main security provider with its forward-deployed forces and extended deterrence, keeping individual guarantees for every ally, whereas these had no obligation to protect each other. At times interests clashed, and allies encouraged disloyalty if it avoided undesired escalations, like in the Second Cross-Strait crisis. This created a rigid security bilateralism that undermined an identity common to the whole system, transcending Washington’s endeavours to revamp its alliances after the Cold War, expecting more from its allies, but keeping intact the core terms of the contract.
Faced with an eroded geopolitical context on the Taiwan Strait, the U.S. flexibilised its stance to Taipei in three ways: first, bringing it into the Indo-Pacific strategy, bolstering its readiness and publicising its military support; secondly, softening the self-imposed restrictions guiding contacts, giving Taiwan sovereign state-like treatment and performing high-level visits; and third, advocating ROC observer status in international forums, assisting it in expanding its diplomatic space. The U.S. encourages allies to follow through; yet this is problematic given the risk of directly antagonising China, and the U.S.’s mixed signals over its own commitment.
Enter Japanese and Korean expectations on a contingency.
Pressured by Beijing’s naval expansion and routinising presence around the Diaoyu/Senkaku islands, and added to the possibility of abandonment by the Trump administration, Prime Minister Shinzo Abe took drastic steps to relax Japan’s security constraints, aiming to retain the U.S. interest in Asia, but also to hedge against uncertainty. This included reinterpreting Article 9 and pushing supporting legislation, revising the U.S.-Japan Guidelines and restructuring the Self-Defence Forces (SDF), enabling participation in collective self-defence operations even when it is not attacked. Amid rising fears that Russia’s invasion of Ukraine inspired similar behaviour in East Asia, and with Beijing’s reaction to Nancy Pelosi’s visit to Taiwan exposing its vulnerabilities, Tokyo prompted additional reforms, acquiring stand-off weapons, pivoting to NATO and Southeast Asia, claiming unmatched leadership in helping Ukraine, and further easing restrictions on security cooperation, concretely in lethal weapons exports.
Much is debated about the special bond between Japan and Taiwan, buttressed by high-profile visits and statements by conservative hawks, Japanese solidarity with Taiwan’s international space, mentions to the status quo following the 2021 Biden-Suga summit and rising mistrust in Sino-Japanese ties, can prompt a broader role for Japan in a contingency. Still, a majority of Japanese oppose the SDF fighting frontally the PLA, given sensitivities of too-close U.S.-Japan ties and anti-militarism stances. Apart from governmental clarifications that its official positions remain unchanged, Japan’s reforms should be understood as hedging plus: boosting its own capability to raise the costs of an invasion, yet avoiding triggering a conflict by recklessly provoking China. History, economy and geography also oblige Tokyo to bear decent relations with Beijing. Thus, it avoids requests for direct military ties or passing its own Taiwan Relations Act, while it prefers engaging Taiwan when relations with China are stable.
Despite their Cold War “anti-Communist alliance,” South Korea has since been distant in its approaches to Taipei. This is underpinned by its balanced diplomacy driven by the existential threat of its heavily armed neighbour to the North, and the need to coexist with powers whose cooperation is crucial to stabilise the Korean Peninsula. Added to President Moon Jae-in’s engagement policy to North Korea, Seoul had no incentive to provoke China over Taiwan. However, the failure of the Trump-Kim summits, rising polarisation in Korean politics and deeper strategic differences with Beijing over Pyongyang prompted Seoul to realign with the U.S., making its first-ever mention of Taiwan since severing relations in 1992, escalated by President Yoon Suk-yeol amid his pivot to the Indo-Pacific.
But this tilt owed less to genuine concerns about Taiwan than to preventing further diversion of U.S. attention from the Peninsula. ROK Cabinet-level officials forgo visiting Taipei, and they distance themselves from supporting Taiwanese international space. Despite evidence of parliamentary diplomacy quietly elevating ties, both limit contacts to the minimum, evidenced by no mutual official delegations attending inaugurations. Diplomatic blunders and Taiwan-Korea rivalry in the economy, innovation, or U.S. assurances further erode the will to narrow the distance. Seoul is also sensitive to discussing the strategic flexibility of U.S. forces outside the Peninsula, which added to Kim’s expanded missile tests and driving vehicles, amendments to its nuclear and reunification policies, and restored ties with Moscow, compelling Korea to focus on countering Pyongyang’s threats. It remains to be seen whether Yoon’s pivot survives his impeachment, especially in a future liberal administration, or will be buried in time.
Looking forward: The need for restraint.
This underscores the relevance of considering the terms of the contract and allies’ agency in determining their ability and willingness to contribute in a crisis. Japan and Korea share an interest with the U.S. in stabilising the Taiwan Strait, but perhaps not the means: both sustain intentionally ambiguous stances, neither denying nor confirming how they would respond to conflict. Yet both alliances remain tight, and failing to act would seriously damage credibility. Therefore, what Tokyo and Seoul do depends on their interests and assessments of the situation; however, there is a need for restraint, as strategic clarity would not help but rather undermine Taiwan’s security, as shown by Nancy Pelosi’s visit.
Carlos Francisco Torres Morales is an MSc Politics and International Relations of East Asia student at SOAS, University of London. He previously got a BA in International Relations from Universidad de las Américas Puebla (UDLAP), Mexico, where he was a member of the Honours Programme. His interests comprise geopolitics, security, and international relations of East Asia and Mexico’s foreign policy in the region. This commentary was based on a condensed version of his Master’s dissertation, presented during the SOAS 2025 Taiwan Summer School.
This article was published as part of a special issue on ‘SOAS Taiwan Studies Summer School 2025‘.
Taiwan Insight 