Despite all their differences and disagreements, the United States and China have both recently launched attacks against big technology giants. In the US, the Federal Trade Commission has accused Facebook of breaking antitrust laws by monopolising through vertical and horizontal acquisition of social media start-ups and well-established competitors such as Instagram and WhatsApp. Facebook’s massive collection of user data makes it possible to impose digital colonialism and profit from its users. Similarly, Didi Chuxing is under investigation by Chinese regulators over charges of anticompetitive behaviour and disorderly capital expansion . In addition, its unauthorised collection and misuse of customer information prompted the government to remove Didi from app stores over data privacy concerns. Chinese regulators are intensifying data protection and online scrutiny amid broader government moves to curb dominant internet platforms. US antitrust enforcement methods can include fines, splitting up companies and undoing acquisitions. A lack of enforcement can be seen, though, as Big Tech firms exert more influence on policymaking by spending large amounts of money lobbying the government . US agencies and courts employ more aggressive antitrust remedies to confront monopolistic behaviour. However, they have not cracked down on the tech giants, which can be a form of national strength and civic power. In China, the government has not forced firms to split up, though it does sometimes unwind acquisitions . Additionally, China imposes “reputation sanctions”, a strategy where the authorities strategically leverage state media to inflict reputational damage on Big Tech firms. Since fines are unlikely to make a substantial dent in a large firm’s fortunes, the moves by Chinese regulators could have longer-lasting effects on Big Tech, such as dire consequences for a firm’s stock price . The moves by both the US and China are signals about enforcing antitrust policies, but neither country wants to destroy Big Tech . The synchronisation of their approaches on the issue reflects the fact that antitrust policy is less about addressing market anomalies. While it is important to tie tech giants’ hands to allow small and medium-sized enterprises opportunities to grow, antitrust policy can seem like nothing but a multifunctional regulatory tool which is also meant to serve political purposes. Since Big Tech has the potential to obstruct free speech, promote misinformation and become a new political instrument in itself, the Antitrust Division of the US Department of Justice has said it expects “greater openness and free speech on platforms”. US antitrust policy also aims to ward off cyberattacks, and limiting the size of technology companies could have repercussions on cybersecurity. There are growing concerns over data security for China, especially in light of intense competition with the US. Beijing wants to achieve data nationalisation and keep Big Tech firms from building a giant database of Chinese people’s personal information. Thus, its antitrust policy aims to strengthen the state’s control over tech capital, promote the development of the platform economy and nudge Chinese Big Tech firms towards innovations that help China achieve technological self-sufficiency . Although political considerations have motivated China and the US to apply somewhat similar approaches when dealing with Big Tech, their domestic political context differs significantly. This will have important implications for possible US-China technological decoupling through three possible channels. First, the different power dynamics between Big Tech firms and their respective governments could affect the pace at which China and the US detach from each other. Chinese Big Tech agrees to government demands promptly, while US tech giants still have large amounts of leverage against the authorities. Second, China is likely to invest whole-of-society efforts in frontier technology domains such as artificial intelligence, 5G, robotics and semiconductors. For example, the China Development Bank has announced increased financial support for technology innovation. Meanwhile, the US Senate passed the Innovation and Competition Act in May, calling for more significant investment in AI and other technologies. Third, US-China decoupling might also come in many niche areas of technology, aside from frontier domains. For example, in response to government directives, Chinese gaming giant Tencent has adopted facial recognition technology in an effort to prevent young people from overindulging in games. This move, which would be inconceivable in the US, suggests a future divergence in the application and development of facial recognition technology between the two countries and a decoupling in that area, driven by social values. Therefore, breaking up Big Tech has enormous implications for how technological decoupling between the two countries might play out. This is not because of a tit-for-tat pattern of geopolitical competition , as some believe. Rather, the decoupling would be a result of the disparity between the two country’s domestic governance frameworks for technology. China and the US are adopting policy approaches that are unconsciously causing them to drift further apart. To avoid this decoupling, greater dialogue and cooperation in technology governance through bilateral engagement is needed. Ke Meng is Hua Yu Associate Professor of the School of Public Policy and Management at Tsinghua University. Yuke Li is a researcher with the College of Engineering at the Westlake Institute for Advanced Study. Delan Lou contributed to the research for this article