The politics of deterrence

Does nuclear deterrence really make us safer? As Britain doubles down on military preparedness, we must question whether the logic of deterrence is undermining the pursuit of lasting peace, and whether Scotland could offer a different vision of security.

We are being told to prepare for war. The language of escalation, deterrence and national resilience has returned to British politics, accompanied by warnings that Europe must be ready for a major conflict by 2030. Scotland is now expected to contribute to renewed UK-wide contingency planning, including a modern version of the Cold War-era War Book. These preparations may be prudent. But there is a danger in allowing the possibility of war to become the organising principle of our politics, rather than a danger we should be working to prevent.

Neil Mackay's argument that Scotland's opposition to nuclear weapons undermines European security raises an important question: what does it mean to take the threat of war seriously? But the answer cannot simply be to prepare to fight one. We must also ask whether the security arrangements we maintain are making conflict less likely, and whether we have become so accustomed to the logic of deterrence that we struggle to imagine security beyond it.

Nuclear deterrence rests on a paradox. The purpose of nuclear weapons is to prevent their use. Britain maintains its Trident system on the assumption that the credible threat of devastating retaliation will deter an adversary from attacking. The logic of mutually assured destruction is that neither side can launch a nuclear strike without risking its own destruction. The weapons preserve peace because the consequences of using them would be catastrophic.

But deterrence is a theory about behaviour, not a guarantee of safety. It depends on leaders making rational calculations, correctly interpreting their adversaries' intentions and maintaining control during moments of extreme pressure. It cannot eliminate the possibility of miscalculation, accident or escalation. Nor can it ensure that every crisis will unfold according to the assumptions on which the system depends.

There is a fundamental tension here. To deter an attack, the threat of retaliation must be credible. Yet the credibility of that threat depends on maintaining the possibility of an act whose consequences could be irreversible. We are asked to trust that nuclear weapons will preserve peace while accepting that their continued effectiveness depends on the willingness to use them.

This does not prove that deterrence has never prevented conflict. It may have contributed to restraining direct military confrontation between nuclear-armed powers. Nor does it follow that abandoning nuclear weapons would automatically produce a more peaceful world. But the fact that deterrence may have prevented certain attacks does not settle the question of whether our present dependence on it is sustainable, or whether it creates risks of its own.

International relations offers a useful way of understanding this problem: the security dilemma. When one state increases its military capabilities to protect itself, another may interpret that expansion as a threat and respond in kind. The first state then sees the response as confirmation of its original fears. Each side's attempt to become more secure can leave both feeling less safe.

This does not mean that all states are equally responsible for conflict, or that Russia's invasion of Ukraine can be excused as a misunderstanding. Russia chose to invade, and Ukraine has every right to defend itself. The security dilemma is not a device for erasing responsibility. It helps explain how military competition can become self-reinforcing, even as individual states claim to be acting defensively.

The question, then, is not whether Britain should ignore Russian aggression. It is whether responding to insecurity through military expansion alone can provide a durable solution. If every increase in capability prompts another increase in response, the result may be a more heavily armed continent without a corresponding increase in trust or stability.

That is important as the UK prepares for the possibility of a major European conflict. Contingency planning is not evidence that war is inevitable, and governments have a responsibility to prepare for emergencies. But warnings about a possible conflict by 2030 should be scrutinised, not treated as predictions that settle the debate. We should ask what evidence supports these assessments, what kinds of conflict are being anticipated, and what is being done alongside military preparation to reduce the likelihood of them occurring.

We should also recognise the interests that shape defence policy. Military institutions have legitimate responsibilities to identify threats and secure the capabilities they need. Defence companies, meanwhile, stand to benefit from government contracts and long-term procurement programmes. The existence of those interests does not demonstrate that warnings about war are manufactured. It does mean that decisions involving enormous public expenditure should be open to scrutiny, particularly when urgency risks narrowing the range of policies considered politically acceptable.

There is a further problem with treating nuclear deterrence as synonymous with national security: it can obscure the other vulnerabilities that governments must address. Scotland's dependence on undersea cables and other critical infrastructure is a case in point. The disruption of communications infrastructure could have serious consequences for economic and social life, particularly for island communities. The UK Government has recognised the need for stronger coordination and resilience in protecting subsea cables. Nuclear weapons cannot, by themselves, solve these practical problems of national security.

“Preparation is not prevention, and the capacity to destroy an adversary is not the same as the capacity to build a more secure world.”

A country can possess the capacity to inflict catastrophic destruction and remain vulnerable to disruption of the systems on which its population depends. A serious defence policy must consider both. This is not an argument for replacing one form of defence with another, but for asking whether our priorities reflect the full range of threats we face.

It is also why diplomacy cannot be treated as a secondary consideration, something to return to once military preparations are complete. Negotiation is not a guarantee of peace. States can negotiate in bad faith, agreements can be broken, and dialogue cannot substitute for the capacity to resist aggression. Yet military strength cannot resolve every political dispute, and the ability to retaliate is not the same as the ability to prevent a crisis from escalating.

In his discussion of negotiation, George Friedman argues that the outcome of a war depends not only on military capability but also on resources, public support and the political survival of leaders. When neither side can achieve its objectives outright, the possibility of a settlement becomes increasingly important. The implication is not that negotiation will always succeed, but that wars ultimately confront political limits that military power alone cannot overcome.

That is a useful corrective to a political culture in which strength is increasingly measured through weapons, spending and readiness. Security requires the capacity to defend against aggression, but it also requires channels of communication, arms-control agreements and diplomatic relationships that reduce the risks of miscalculation. These mechanisms do not eliminate conflict. They can help prevent disputes from becoming catastrophic.

The distinction between deterrence and peacebuilding is crucial here. Preventing an attack is not the same as creating the conditions for lasting peace. A nuclear deterrent may be intended to discourage a particular form of aggression, but it cannot resolve territorial disputes, rebuild diplomatic relationships or establish the limits necessary to manage military competition. Nor would unilateral disarmament automatically accomplish those things.

The international movement behind the Treaty on the Prohibition of Nuclear Weapons represents an attempt to challenge the assumption that nuclear weapons must remain a permanent feature of international security. As of October 2026, 75 states are parties to the treaty, which prohibits its members from developing, possessing or using nuclear weapons. The nuclear-armed states have not joined, limiting its immediate reach. Nevertheless, its existence demonstrates that the international community is not unanimous in accepting nuclear deterrence as the only credible foundation for security.

For Scotland, this opens a question larger than whether Trident should remain on the Clyde. Britain maintains a continuous at-sea nuclear deterrent, but the Trident missile system depends on American technology and a shared stock of missiles, while the UK retains its own warheads and operational responsibility. This is a close strategic partnership, not a simple arrangement in which Washington controls every British nuclear decision. Yet it raises legitimate questions about dependence, sovereignty and the relationship between Britain's nuclear ambitions and its actual security needs.

An independent Scotland could choose a different role in international affairs: one that combines conventional defence and cooperation with European partners with a stronger commitment to nuclear disarmament. Isobel's suggestion of a Celtic peace alliance offers a possible starting point. Scotland, Wales and Ireland have different constitutional positions and security arrangements, and shared opposition to nuclear weapons would not automatically make them a coherent geopolitical bloc. But cooperation on arms control, disarmament and conflict prevention could give that idea substance.

Such a role would require more than removing nuclear weapons from Scottish territory. It would mean investing in diplomacy, supporting international agreements and developing a credible approach to the practical defence of Scotland. It would also require acknowledging that peace cannot be secured by good intentions alone. A peace-promoting foreign policy must be capable of confronting aggression without accepting permanent escalation as inevitable.

The choice is not between preparing for war and pretending war cannot happen. It is between treating military preparedness as the entirety of security and recognising that preventing conflict is also a strategic responsibility.

Nuclear weapons may be defended as instruments of peace, but that claim deserves the same scrutiny as any other defence policy. If our security depends on the permanent threat of catastrophic retaliation, we should ask what happens when deterrence fails, when leaders miscalculate or when a crisis escapes their control. And we should ask whether sufficient political effort is being devoted to reducing those risks in the first place.

Preparing for war may sometimes be necessary. But preparation is not prevention, and the capacity to destroy an adversary is not the same as the capacity to build a more secure world. If Scotland is to have a meaningful debate about Trident, it must be about more than whether nuclear weapons are necessary. It must also be about what kind of security we want, what risks we are willing to accept, and whether we are prepared to invest as seriously in preventing catastrophe as we are in preparing for it.