What Quantum Technology Means for Defence

Quantum technology has long existed at the edge of scientific possibility. For decades, it remained largely confined to research laboratories and theoretical physics. Today, however, governments, defence organisations, and industry leaders increasingly view quantum technology as a strategic capability that could fundamentally reshape military operations, intelligence gathering, communications, navigation, and decision-making (7, 8, 11).

Much like the emergence of radar, nuclear technology, or artificial intelligence before it, quantum technology is attracting significant defence investment because of its potential to create both strategic advantages and strategic vulnerabilities (9, 11, 13). While many quantum capabilities remain in development, the race to exploit them is already underway.

Understanding Quantum Technology

Quantum technology refers to systems that exploit the principles of quantum mechanics, the branch of physics that governs the behaviour of matter and energy at extremely small scales. Unlike conventional digital systems that rely on binary bits represented as either a one or a zero, quantum systems use quantum bits, or qubits, which can exist in multiple states simultaneously (8, 11).

This characteristic enables entirely new approaches to computing, sensing, communications, and measurement. Defence planners are particularly interested in four broad areas: quantum computing, quantum sensing, quantum communications, and quantum positioning, navigation, and timing systems (3, 7, 11).

Each of these capabilities has the potential to alter how militaries gather information, secure networks, navigate contested environments, and gain decision superiority on future battlefields (2, 7, 9).

Quantum Computing and Military Advantage

Quantum computing remains the most widely discussed aspect of quantum technology. Although practical large-scale quantum computers are still under development, their potential implications are profound (5, 7, 11).

Current military and intelligence organisations rely heavily on encryption to protect communications, operational plans, intelligence databases, and critical infrastructure. Many existing encryption methods are considered secure because conventional computers would require impractical amounts of time to break them. Quantum computers may eventually overcome these limitations by solving specific mathematical problems exponentially faster than traditional systems (5, 10, 11).

This prospect has prompted growing concern among governments and defence agencies worldwide. Adversaries may already be collecting encrypted information today with the expectation that future quantum computers could decrypt it years later. Sensitive military information that remains valuable over long periods could therefore become vulnerable even before practical quantum computers fully emerge (5, 11).

At the same time, quantum computing may offer substantial operational benefits. Future systems could dramatically improve optimisation problems associated with logistics, force deployment, route planning, resource allocation, and battlefield simulations. Defence organisations could gain the ability to model complex operational scenarios at speeds currently impossible using classical computing systems (4, 5, 10).

Quantum Sensing and the Future Battlefield

While quantum computing often dominates headlines, many experts believe quantum sensing may deliver military benefits sooner than fully capable quantum computers (2, 3, 6).

Quantum sensors exploit quantum effects to achieve exceptionally precise measurements of physical phenomena such as gravity, magnetic fields, acceleration, and time. These sensors have the potential to dramatically improve the detection, tracking, and identification of objects across land, sea, air, and space domains (2, 3, 6).

For defence applications, this could mean enhanced submarine detection, improved intelligence collection, more accurate targeting systems, and greater awareness of battlefield activity. Quantum sensing may also help identify concealed infrastructure, underground facilities, or otherwise difficult-to-detect military assets (3, 6).

Perhaps most importantly, quantum sensors could reduce dependence on satellite-based navigation systems. Modern military operations rely heavily on Global Navigation Satellite Systems (GNSS), including GPS. However, these systems are increasingly vulnerable to jamming, spoofing, and disruption. Quantum navigation systems could enable forces to operate accurately even when satellite signals are unavailable or contested (2, 3, 9).

In an era where electronic warfare capabilities continue to expand, this represents a potentially significant strategic advantage (6, 9).

Securing Communications in the Quantum Age

Quantum communications represent another major area of defence interest (7, 8, 11).

One of the most promising applications is Quantum Key Distribution (QKD), a method of exchanging encryption keys using quantum principles. Unlike conventional encryption systems, QKD can reveal attempts to intercept communications because observation itself alters the quantum state being transmitted (8, 11).

For military organisations, secure communications are fundamental to command and control, intelligence sharing, and operational coordination. Quantum communications could provide unprecedented levels of security for sensitive information networks (7, 11).

Several nations are already investing heavily in quantum communication infrastructure, including secure fibre networks and satellite-based quantum communication systems. Although challenges remain regarding scalability, range, and cost, the strategic implications are significant. Nations that successfully deploy robust quantum communication networks may gain substantial advantages in protecting critical military information (7, 8, 11).

Strategic Competition and National Security

The global competition surrounding quantum technology increasingly resembles earlier technological races that shaped military power throughout history (8, 11, 13).

Major defence powers including the United States, China, the United Kingdom, Australia, and members of the European Union have all launched significant quantum initiatives. Defence ministries and military research organisations are investing heavily in quantum research programmes, recognising that leadership in this field could influence future military balances (2, 7, 13).

Importantly, quantum technology should not be viewed solely through the lens of military capability. It also represents an industrial, scientific, and economic competition. Countries that establish strong quantum ecosystems are likely to attract talent, investment, and technological innovation across multiple sectors (1, 8, 13).

This broader strategic significance explains why quantum technology is increasingly appearing in national security strategies and defence modernisation plans around the world (7, 8, 13).

Challenges and Ethical Considerations

Despite the enthusiasm surrounding quantum technology, substantial challenges remain (4, 12).

Many quantum systems are still experimental, requiring specialised environments and complex engineering solutions. Significant technical barriers must be overcome before many anticipated defence applications become operational realities (2, 4).

There are also important governance and ethical questions. Quantum technologies could alter intelligence collection capabilities, create new cyber security risks, and potentially widen technological gaps between nations. As with artificial intelligence, policymakers face the challenge of encouraging innovation while ensuring responsible development and deployment (12).

International cooperation, standards development, and strategic governance frameworks may therefore become increasingly important as quantum technologies mature (12).

Looking Ahead

Quantum technology is unlikely to transform defence overnight. However, its long-term implications are difficult to ignore.

The combination of quantum computing, sensing, communications, and navigation capabilities has the potential to influence nearly every aspect of military operations. From protecting sensitive information and improving battlefield awareness to enabling new forms of decision support and resilience in contested environments, quantum technologies may become foundational components of future defence systems (3, 6, 7, 11).

For defence organisations, the question is no longer whether quantum technology matters. The challenge now is understanding how quickly these capabilities will mature, where they will deliver the greatest operational impact, and how to prepare for a future in which quantum-enabled advantages increasingly shape strategic competition (7, 8, 9, 11).

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References:

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9.        Krelina, M., & Dúbravčík, D. (2023, February). Quantum technology for defence: What to expect for the air and space domains. Joint Air Power Competence Centre. https://www.japcc.org/articles/quantum-technology-for-defence/

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11.  NATO Science and Technology Organization. (n.d.). Quantum technology for defence and security. https://www.sto.nato.int/document/quantum-technology-for-defence-and-security/

12.  Oxford Internet Institute. (2024). How quantum technology for defence can be developed ethically, and why it needs to be governed now. University of Oxford. https://www.oii.ox.ac.uk/news-events/how-quantum-technology-for-defence-can-be-developed-ethically-and-why-it-needs-to-be-governed-now/

13.  Quantum Australia. (n.d.). Defence. https://www.quantum-australia.com/defence