Nuclear weapons may no longer be credible deterrents in an era of hypersonic missiles and AI-driven warfare. Tom Sauer suggests that modern conventional weapons could ultimately replace nuclear arsenals, reshaping global security without risking nuclear annihilation
Nuclear weapons are perceived as the ultimate deterrent. Yet their actual use contradicts international humanitarian law — and this raises doubts about their deterrent credibility. Both the Nuclear Non-Proliferation Treaty (NPT) and the Treaty on the Prohibition of Nuclear Weapons (TPNW) call for their elimination. Even proponents of nuclear deterrence often accept disarmament as an ultimate goal but see it as unrealistic. Such people argue that nuclear weapons provide stability, and that we have no feasible alternative.
In a recent paper for the EU Non-Proliferation and Disarmament Consortium, I offer two key arguments to inform the ongoing debate. First, emerging and disruptive technologies — including artificial intelligence, cyber capabilities, and advanced conventional weapons like hypersonic missiles — undermine nuclear stability. Second, these same technologies, particularly modern conventional missiles, could form the foundation of an effective future deterrent. Indeed, they could even replace nuclear weapons entirely.
Emerging and disruptive technologies, including artificial intelligence, cyber capabilities, and advanced conventional weapons such as hypersonic missiles, pose significant threats to strategic stability. Traditionally, nuclear-armed states rely on strategic stability. If they are confident their adversaries cannot fully eliminate their nuclear arsenals through a first strike, they preserve the capacity for a retaliatory second strike. According to deterrence theory, this scenario — known as Mutually Assured Destruction — maintains stability and prevents conflict.
However, technological advancement continually reshapes strategic calculations. New weapon systems are faster, more accurate, and highly manoeuvrable. Modern ballistic, hypersonic, and cruise missiles increasingly threaten early-warning systems, command-and-control structures, and nuclear delivery platforms. Facing these enhanced capabilities, states may place their nuclear forces on heightened alert and adopt pre-emptive postures — often referred to as ‘use-it-or-lose-it’ strategies — which significantly increase instability. Advanced offensive technologies also render missile defences increasingly ineffective.
The theory of Mutually Assured Destruction maintains stability and prevents conflict. But emerging and disruptive technologies pose significant threats to strategic stability
Moreover, modern missiles can more effectively circumvent missile defence systems. Additionally, advancements in Big Data and AI — such as swarm sensors — may increase ocean transparency, making nuclear submarines detectable and vulnerable. This development could eliminate secure second-strike capabilities, severely eroding strategic stability.
New technologies pose substantial risks to nuclear stability. Although some technologies might benefit arms control verification and disarmament efforts, scholarly consensus indicates their negative impacts significantly outweigh the positives. While future innovations might restore stability, this remains uncertain. They could just as easily exacerbate instability; at this stage, we simply cannot be sure.
Fortunately, there is a possible way out of this conundrum. Some of these new weapon systems could serve deterrent purposes rather than warfighting roles. In particular, hypersonic missiles armed with advanced conventional warheads might eventually allow states to reduce and ultimately eliminate their nuclear arsenals, as mandated by the NPT and the TPNW. Major nuclear powers, including the United States, Russia, and China, increasingly emphasise conventional deterrence in their strategic documents — not as a substitute but as a complement to nuclear deterrence. This argument proposes going a step further: gradually replacing nuclear deterrence entirely with advanced conventional deterrence.
Critics argue that conventional weapons provide weaker deterrence and might lead to more frequent conflicts. However, the relative credibility of nuclear versus conventional deterrence remains debatable. Nuclear weapons are enormously destructive and thus inherently lack credibility as practical deterrents. Conversely, earlier generations of conventional weapons were not destructive enough to reliably deter adversaries. Modern conventional weapons occupy a valuable middle ground — similar to the ‘Goldilocks’ scenario. Such weapons are sufficiently fast, precise, manoeuvrable, and destructive to be credible deterrents, but lack the prohibitive destructiveness of nuclear weapons.
Modern conventional weapons are fast, precise, manoeuvrable, and destructive enough to be credible deterrents, but lack the prohibitive destructiveness of nuclear weapons
A significant advantage of moving toward a nuclear-free world is the elimination of nuclear annihilation risks. Of course, persuading nuclear-armed states to commit fully to disarmament through multilateral negotiations will require time. During this transition period, careful management will be essential. Robust arms control measures will remain critical to limit both the quantity and quality of advanced conventional arsenals.
A world without nuclear weapons would not eliminate conflict altogether. Thorough assessments of the comparative costs and benefits of nuclear versus conventional deterrence remain essential. Nevertheless, a nuclear-free world — mandated by international treaties — might become more politically achievable as a result of rising awareness of nuclear escalation risks highlighted by conflicts such as the Ukraine war.
Paradoxically, a nuclear-free world might become more politically achievable as a result of rising awareness of nuclear escalation risks
Emerging technologies like hypersonic missiles, despite their risks, could — paradoxically — facilitate this shift by providing credible alternatives to nuclear arsenals. Ensuring a stable transition will require international cooperation, rigorous arms control agreements, and transparency. If successfully managed, these developments could significantly reduce global nuclear threats, and bring the world closer to sustainable security without nuclear weapons.
Tom specialises in international security, in particular nuclear arms control, proliferation, and disarmament.
He has published eleven monographs and edited books, dozens of academic articles in journals, and more than 250 opinion articles.
Security Order and Strategic Alignment in Europe and the Asia-Pacific
co-edited with Yoichiro Sato and Elena Atanassova-Cornelis
Routledge, 2025
Tom studied politics and international politics at FUNDP-Namur, Katholieke Universiteit Leuven, the University of Hull, and the Bologna Center of the Paul H. Nitze School of Advanced International Studies (SAIS) at Johns Hopkins University.
He obtained a PhD in Social Sciences (Politics) from Katholieke Universiteit Leuven.
Tom received a NATO Individual Scholarship (1994–1995), a Rotary Ambassadorial Scholarship (1997–1998), and a Postdoctoral Fellowship of the Research Foundation – Flanders (2002–2008).
He is a former BCSIA Fellow at Harvard University's John F.Kennedy School of Government (1997–1999), and an active member of the Pugwash Conferences on Science and World Affairs.
