Written by Alexandra Whitehead.

Image credit: UK Carrier Strike Group on Operation Highmast by Ministry of Defence, license: Open Government Licence v3.0.

As Britain pledges a move towards “warfighting readiness,” is Taiwan’s sovereign integrity really guaranteed under the UK’s blueprint for national and global security? The answer is yes, but significant improvements are needed.     

Published on the 2nd June 2025, the Strategic Defence Review (SDR) outlines His Majesty’s (HM) Government’s strategy for upholding Britain’s national defences and pledging support for global security. A reflection of rising geopolitical tensions, it was drafted by an external panel of security experts and promises an alliance-centric approach to national and global defence underpinned by increased spending, technological innovation, a boost in regular troops, and a “secure at home, strong abroad” narrative. Under the SDR, the UK is intended to appear as a reliable contributor to the global order and a place where safety is guaranteed at home.

Enter Taiwan

Taiwan enjoys a contested international status dating back to 1949 when Chang Kai-shek (蔣介石) retreated there following his defeat in the Chinese Civil War. Since then, the Chinese Communist Party (CCP) have claimed Taiwan as a province, rejecting its leadership. In response, Taiwan has sought to preserve its political and global autonomy through soft-power means, including humanitarian assistance and semiconductor diplomacy.

Since Xi Jinping’s (習近平) ascension to the Chinese Presidency, Taiwanese sovereignty has found itself increasingly under threat. One of Xi’s primary goals is the realisation of the “Chinese Dream” of “national rejuvenation,” achieved through an aggressive, ideological foreign policy that vows the “inevitable” unification of Taiwan with China. Warships are deployed around Taiwan on an almost-daily basis, and a creeping cyber invasion is turning into a disturbing normality.

Britain’s role in all this is that the animosity between Taiwan and China should be handled by them and them alone, but Britain insists that tensions be mitigated peacefully. It has been this way since 1972 with the signing of a joint communiqué marked by the first exchange of ambassadors between the UK and the People’s Republic of China (PRC) since the start of the Cultural Revolution.  

The Global Importance of the Taiwan Issue

While Britain remains firm on its assumption that Taiwan is a Chinese province, informal, values-based relations between the two have thrived for decades and rising geopolitical tensions in the Indo-Pacific – largely stemming from Xi Jinping’s militarisation of the South China Sea, rejection of international law, and insistence on Taiwan’s diplomatic isolation – has prompted the UK to recognise the island as a strategic asset (in crucial areas such as technology and economic stability) in light of Taiwan’s newfound status as a major flashpoint.

While avoiding any explicit mention of the UK’s Taiwan policy, the SDR’s emphasis on countering China, upholding rules-based order, and strengthening regional partnerships (AUKUS, Global Combat Air Programme) suggests the UK is manoeuvring itself into the role of ‘stability guarantor’ within the Indo-Pacific and pledges support for Taiwanese security. The UK’s Foreign Secretary, David Lammy, first stressed the need to defend Taiwanese sovereignty in a press conference with Anthony Blinken in September 2024 before taking to X (Twitter) to fire a blazing condemnation of China’s destabilising actions in the South China Sea, which includes Taiwan. Lammy’s concerns for Taiwanese statehood are echoed in the SDR by its central theme: Britain’s commitment to “warfighting readiness.” Which, in the context of this document, refers to ramping up military and technological advancements so the UK can adequately defend itself and others against any potential state-on-state conflict. Underscoring concerns about the threats autocratic regimes such as China pose to the global order and the need to defend like-minded partners.

This emphasis on regional stability also indicates Britain’s recognition of Taiwan’s global significance. From an economic standpoint, Taiwan occupies a strategically vital position within global supply chains, with its central role in the production and export of semiconductors and other high-value technological components placing it at the intersection of major trade routes between East Asia, North America, and Europe. This position not only underpins Taiwan’s economic significance but also amplifies its geopolitical relevance. Any conflict over Taiwan is framed as not merely a regional issue but one with far-reaching consequences, implying a desire to deepen defence initiatives.

Similarly, increasing military capability and lethality serve as an indirect show of support for Taiwan. It is an approach emphasising collective regional security, especially under the principle of “Freedom of Navigation.” A recent example of this has been the passing of HMS Spey through the Taiwan Strait. Additionally, bilateral cooperation is being strengthened with Japan, South Korea, New Zealand, and Australia. Strengthening both military presence and focus towards the region suggests Taiwan’s growing centrality within the UK’s defence narrative, and reiterations of China as a “systematic challenge” imply greater attention is being channelled to addressing risks concerning Taiwan.

Albeit indirectly, indirect support is still support, and we therefore see the SDR as Britain’s commitment to strengthening ties with Taiwan by formally recognising the Taiwan Strait as a place of strategic value and interest, highlighting China’s actions in the region as “dangerous,” and through framing engagement as part of a values-based foreign policy.

Promising but Lacking

While setting out a compelling narrative – Britain indeed faces threats not seen since the Cold War – and clear in intent, the SDR falls short in addressing the challenges in the Indo-Pacific arena and is overwhelmingly Eurocentric. It seems contradictory that a document highlighting the strategic importance of the Indo-Pacific as an “economic and political powerhouse” in need of protection ultimately falls short on impact. For Taiwan, overemphasis on Ukraine (though logistically more feasible for the UK because it is geographically closer, and an awful travesty in itself that should not be diminished) spells disaster, signalling the UK’s ultimate priorities lie with how to tackle potential armed conflict with Russia while leaving it vulnerable to China’s increased regional aggression.

There is no explicit contingency planning towards Taiwan, and the support there is hidden between the lines. Not once is Taiwan mentioned by name as an independent entity, only within the context of Chinese actions, and there is no discussion of how the UK would respond militarily to a Taiwan crisis or what the threshold for Britain’s involvement actually is. The SDR is brilliant in delivering a clear-cut approach to Ukraine, but fails to transfer Taiwanese concerns into anything concrete, making the Indo-Pacific appear as a secondary arena.

Next is the question of ambiguity. If you are thinking RUSI’s Matthew Savill is right in how “ambiguity is a threat to the implementation of the Review,” you would be correct: strategic ambition does not account for uncertainty. Despite becoming more outspoken in recent years, official documentations continue to stay clear of explicit alignment with Taiwan, as it shows support without turning heads in Beijing. It is an uncertain tightrope the UK must continually balance – how to navigate values-based international order delivered by Taiwan with China’s bountiful economic opportunities – and stands as one of the thorniest dilemmas in contemporary British foreign policy.

Britain’s ambiguity, while acting as a deterrence tool, risks making the UK appear ill-prepared and ill-committed to supporting Taiwanese sovereignty, delivering nothing but little warning for Beijing and uncertainty for Taipei. The SDR has tried to turn strategic ambiguity into something more effective by turning towards an alliance-led approach to the region; however, such a strategy risks signalling to the Taiwanese that the UK’s presence remains episodic, and falling-back onto your alliances to maintain your ambiguous stance is a poor reflection of a nation painting itself as a global security guarantor.

Concluding Take-Away’s

In short, compared to Britain’s generally more assertive and supportive response in the case of Ukraine, Taiwan’s threat of political absorption by the PRC has elicited a more cautious and measured approach from the UK.

The Strategic Defence Review has certainly been worth the months of anticipation. Its clear roadmap, commitment to measurable targets, and embracement of all the latest gadgets are commendable; however, regarding Taiwan, the narrative remains limited.

Commitments are certainly there concerning values-based engagement, recognition and emphasis of Taiwan’s role in regional stability, and alignment with allies. Yet the UK’s unwillingness to move beyond the ambiguous makes one question whether Britain truly wants their presence in the Indo-Pacific to be anything more than symbolic, and where Taiwan is concerned, hinders the SDR’s effectiveness as a willing guarantor of Taiwanese sovereign integrity against Chinese unification tactics.

Alexandra Whitehead is an MA Taiwan Studies student at SOAS, University of London. Her particular interests lie in the implementation of British Foreign Policy in the Indo-Pacific, Cross-Strait contentions, and military history and defence studies (with special reference to the Greater Chinese Region).

This article was published as part of a special issue on ‘SOAS Taiwan Studies Summer School 2025‘.