Strategic ambiguity, or the deliberate policy of uncertainty as to whether the United States would use force to defend Taiwan against an invasion by the People's Republic of China, has been the centrepiece of US policy towards the Taiwan issue for decades. This paper discusses the factors driving the redefinition of strategic ambiguity and its recalibration throughout Donald Trump's presidency (2017–2021). The fundamental driver of this change was to balance the rising power of the People’s Republic of China (PRC). The paper applied offensive realism as a theoretical framework for its analysis. Under President Donald Trump, Washington modified its policy of strategic ambiguity, explicitly framing relations with Taiwan within a broader Indo-Pacific strategy. While the US retained key elements of strategic ambiguity, including the 'One China' policy, it added new features to deploy it offensively against Beijing's growing regional hegemony. The increased dynamism and unpredictability of relations with Taiwan were matched by a welcoming attitude towards strengthening Taiwanese identity and highlighting the systemic differences between communist China and democratic Taiwan. America stepped up arms sales and encouraged Taiwan to build its self-defence capabilities. Washington engaged in countering Chinese attempts to isolate Taiwan internationally and included it in restructuring global supply chains. Although the United States has not formally revised the boundaries of the 'One China' policy, the modification of strategic ambiguity increased Taiwan's prominence in US-China power competition and pushed back the prospect of peaceful unification.