How China’s quantum race threatens nuclear deterrence

A new frontier of strategic competition is emerging — one that is invisible to the naked eye yet carries consequences as profound as the nuclear revolution of the mid-20th century. 

Quantum technology, spanning quantum computing, quantum communication, quantum sensing and quantum radar, is rapidly transitioning from the domain of theoretical physics to applied military capability. Among the major powers driving this transition, China has moved with unusual alacrity and institutional resolve.

Its advances are not merely technical achievements; they represent a deliberate national strategy to restructure the conditions of strategic competition in ways that challenge existing deterrence frameworks and risk introducing a new and destabilising security dilemma.

China’s quantum programme is unfolding against the backdrop of intensifying great power rivalry. The responses of the US and other powers underscore the strategic implications for international security. By undermining encrypted communications, enhancing surveillance and targeting, and compressing decision-making timelines, quantum technologies risk producing a form of strategic instability that existing arms control mechanisms are wholly unprepared to manage.

Mapping the quantum battlefield

Quantum technology is not a single capability, but a family of applications rooted in the principles of quantum mechanics, including superposition, entanglement and interference.

For defence and intelligence communities, four applications are of primary strategic significance. Quantum computing offers the prospect of solving computational problems that are intractable for classical machines, with direct implications for breaking existing cryptographic standards — such as the Rivest-Shamir-Adelman (RSA) encryption and the elliptic curve encryption (ECC) — that underpin the secure communications of every major military and government on earth. Quantum key distribution (QKD) uses the properties of quantum states to create theoretically unbreakable encryption channels. Quantum sensing and gravimetry offer dramatic improvements in precision navigation, underground detection and submarine tracking, potentially rendering nuclear second-strike assets vulnerable. Finally, quantum radar exploits entangled photons to detect stealth aircraft and low-observable platforms, threatening a key pillar of Western air power doctrine.

The US’s National Institute of Standards and Technology (NIST) has already begun standardising post-quantum cryptographic algorithms, reflecting the urgent recognition that cryptographically relevant quantum computers could emerge within a decade. The urgency is underscored by the threat of ‘harvest now, decrypt later’ strategies, whereby adversaries collect encrypted data today in anticipation of quantum decryption capability tomorrow. This renders the quantum transition not a future problem, but an immediate intelligence and security challenge.

China’s coordinated quantum leap

China’s investment in quantum technologies is extensive, coordinated and explicitly linked to national security objectives. Quantum science was designated a priority under the 14th Five-Year Plan (2021–2025), and the sector has received sustained funding through the National Natural Science Foundation of China, the Ministry of Science and Technology, and the People’s Liberation Army (PLA). China’s spending on quantum research is estimated to have exceeded US$15 billion, a figure that dwarfs comparable Western national programmes in scale, though direct comparisons are complicated by opacity in Chinese military research budgets.

The most internationally visible achievement has been the Micius quantum satellite, launched in 2016 under the Quantum Experiments at Space Scale (QUESS) project. Micius demonstrated groundbreaking satellite-based QKD, enabling quantum-secured communications over intercontinental distances and performed quantum entanglement distribution over a record-breaking distance of 1,200 kilometres. This was not a laboratory demonstration but a prototype of an operational quantum communication backbone.

China has since announced plans to expand this into a global quantum satellite network — an ambition that, if realised, would give Chinese governmental and military communications an encryption architecture resistant to interception by any adversary with classical computing capability.

On the quantum computing front, the University of Science and Technology of China (USTC), under the direction of physicist Pan Jianwei, developed the Jiuzhang photonic quantum computer, which demonstrated quantum advantage in specific computational tasks. The subsequent Zuchongzhi superconducting processor performed calculations that would take classical supercomputers thousands of years. These achievements signal that China is not trailing behind but competing directly with American and European quantum computing programmes, with Google, IBM and their governmental backers.

Crucially, China’s quantum programme is integrated with PLA modernisation objectives. The Chinese Academy of Military Science has published research on quantum radar, quantum navigation for submarines and ballistic missiles as well as quantum-enhanced electronic warfare. The strategic logic is coherent: by developing quantum sensing capable of detecting submerged submarines, China could theoretically degrade the survivability of US and allied nuclear second-strike forces, shifting the balance of mutually assured destruction in ways that are deeply destabilising.

Washington’s stumbling response

Washington has recognised the quantum challenge, though its response has been characterised by bureaucratic fragmentation as much as strategic clarity. The National Quantum Initiative Act of 2018 established a federal framework for coordinating quantum research across the Department of Energy, the National Science Foundation, and the National Institute of Standards and Technology, committing over US$1.2 billion in initial funding. The programme has since been renewed and expanded, with the DARPA Quantum Network Science programme pursuing practical military communications applications.

The intelligence community has been more candid about the risks. The Office of the Director of National Intelligence has consistently flagged quantum computing as a strategic threat in its annual Worldwide Threat Assessment, noting that a cryptographically relevant quantum computer would compromise virtually every encrypted system in the US government and defence establishment. The National Security Agency has issued guidance mandating a transition to post-quantum cryptographic standards across classified networks, an undertaking of extraordinary logistical complexity given the depth of legacy systems.

Export controls on semiconductor technology, tightened significantly under both the Donald Trump and the Joe Biden administrations, have sought to slow China’s access to the advanced chips necessary for quantum computing development. The Bureau of Industry and Security has added numerous Chinese quantum research entities to its Entity List, restricting technology transfers. Whether these measures are sufficient, given China’s domestic semiconductor ambitions and alternative sourcing strategies, remains an open question.

Russia and other contenders

Russia is pursuing quantum technologies but from a significantly weaker industrial and scientific base. Rosatom, the state nuclear corporation, has taken a leading role in quantum computing development, launching a five-year national programme in 2020 with a target of producing a 100-qubit quantum computer. Russian academic institutions retain strong theoretical expertise, and military research institutes have conducted parallel work on quantum sensing and communication. 

However, the compounding effects of sanctions following the 2022 invasion of Ukraine, combined with brain drain among scientific talent, have constrained the pace of development. Russian quantum ambitions are real, but they are currently outpaced by both the US and China.

Beyond these three powers, quantum programmes of varying scale exist in the UK, France, Germany, Canada, Australia, India and Japan. The UK National Quantum Strategy, launched in 2023 with £2.5 billion committed over ten years, reflects a recognition that quantum capability will become a prerequisite of serious defence and intelligence partnerships. India has similarly committed substantial resources under its National Quantum Mission, with particular attention to QKD for securing strategic communications.

Nuclear deterrence under threat

The concept of the security dilemma, first articulated by John Herz and developed by Robert Jervis, describes the dynamic by which one state’s defensive measures are perceived as offensive threats by others, triggering reciprocal responses that leave all parties less secure. Quantum technology is generating precisely this dynamic, with the additional complication that it is largely invisible to the monitoring mechanisms that have historically provided reassurance.

Consider the strategic logic from Beijing’s perspective. The US maintains overwhelming conventional and nuclear superiority. Quantum sensing, if developed to operational maturity, could allow the US to track Chinese ballistic missile submarines, compromising China’s second-strike capability. China’s investment in quantum communication is thus — at least partly — a defensive response to that vulnerability, seeking to secure its own command and control from American signals intelligence. But the same sensing and computing capabilities developed for defence create offensive potential, threatening American encrypted communications and satellite navigation systems.

The CSIS has assessed that quantum technologies could accelerate the erosion of nuclear deterrence stability by undermining the survivability of second-strike forces, compressing warning times through enhanced sensing, and degrading the encrypted command links through which nuclear forces are controlled. This creates what strategists have begun calling a ‘quantum stability gap’, a period in which quantum advantages are asymmetric, partial and opaque enough to incentivise pre-emptive action under crisis conditions.

Unlike nuclear weapons, quantum technologies generate no easily observable signatures. There are no test sites, no mushroom clouds, no seismic signatures. A state might develop a cryptographically relevant quantum computer in a laboratory setting, with no external indicator available to adversaries. The absence of verifiable transparency removes the basis for confidence-building measures and makes the security dilemma structurally more acute.

An obsolete framework for the quantum era

The strategic implications of the quantum arms race are considerable and, to date, substantially under-addressed by the international community. Arms control architecture, from the Non-Proliferation Treaty to the Intermediate-Range Nuclear Forces Treaty, was designed for a world of kinetic weapons and detectable signatures. It offers no framework for managing the risks posed by quantum-enabled capabilities.

Several priorities warrant attention. First, post-quantum cryptographic migration must be accelerated across all critical infrastructure, not merely classified government networks. The NIST post-quantum standards released in 2024 provide a technical basis, but implementation timelines remain dangerously slow across much of the private sector and allied governments. Second, multilateral dialogue on quantum stability, analogous to early Cold War discussions on nuclear doctrine, is urgently needed. The Geneva-based multilateral disarmament community has yet to develop a serious agenda on quantum security risks. Third, intelligence-sharing arrangements among allied states on quantum developments, modelled on existing Five Eyes frameworks, could reduce the information asymmetries that make the security dilemma more dangerous.

Navigating uncertainty

China’s quantum leap is not a distant prospect. It is an unfolding strategic reality, driven by institutional commitment, substantial investment and a clear-eyed appreciation of the military applications of quantum science. The US is responding — but without the coherence or urgency that the challenge demands. Russia and other powers are engaged. The result is a nascent quantum arms race that is already generating the conditions for a new and poorly understood security dilemma.

The irony of the quantum era is that a technology rooted in the probabilistic uncertainty of subatomic particles is introducing a new form of strategic uncertainty at the level of great power relations. Managing that uncertainty will require not only technical investment but also the development of new strategic concepts, new arms control frameworks and a quality of diplomatic imagination that the international community has so far failed to demonstrate. The quantum age is arriving, whether the world’s governments are ready for it or not.

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