The credibility of nuclear deterrence rests on whether an adversary believes a threat will be carried out, yet individual leaders and public attitudes—especially in democracies—are increasingly dictating whether those signals are believed. A new analysis from the Carnegie Endowment for International Peace argues that domestic politics, long treated as background noise, now sits at the center of whether deterrence holds.
The Cold War Architecture
Deterrence theory developed its modern shape during the Cold War as the scholarship and practice of how threats of force convince another party to refrain from action. The logic rests on a calculation: a prospective attacker is deterred when they believe the probability of success is low and the costs of attack are high. That equation depends on two pillars—capability, the physical arsenal and delivery systems, and resolve, the political will to use them. For decades, strategists treated resolve as a material fact, visible in tripwire troops, alliance treaties, and hardened command posts.
Resolve as a Political Decision
What the material view misses is that the decision to launch a nuclear weapon is profoundly political. It falls to a head of state, a politician subject to individual psychology and accountable to a vulnerable public. Looking inside the state making the threats—its partisan divisions, its leadership style, its electoral calendar—offers a more accurate read on resolve than counting silos alone. Nuclear signals only work for deterrence if they are believed; if an adversary views them as empty bluster, they lose their efficacy to either deter or coerce.
Polarization and Populist Rhetoric
Media accounts suggest nuclear bluster is more common than ever. Russian leaders have frequently voiced a range of nuclear threats and signals as the war in Ukraine has dragged on. U.S. President Donald Trump has used apocalyptic language toward Iran that some observers considered an implicit nuclear threat.
Arms Racing Without Guardrails
The rhetorical escalation coincides with a quantitative buildup. Military stockpiles globally have increased by about 130 warheads, and all nine nuclear-armed countries are undergoing modernization. China’s nuclear arsenal is growing rapidly, and its nuclear enterprise plays a more central role in shaping doctrine and posture. Strategic arms control has faded as a tool for managing arms racing and crisis escalation concerns. Perennial tensions between India and Pakistan have exploded, subsided, and resumed.
European Recalibration
European governments are asking how they can achieve deterrence effects with a weakened U.S. extended deterrent. Researchers at the International Centre for Defence and Security warn that assuming U.S. extended nuclear deterrence is stopping Russia from doing something specific at this moment is analytically fraught. Stability, they argue, is not “we are so powerful that they will try nothing”; it is “we are both armed with deadly weapons so both of us are cautious.”
Franco-British Operationalizing
On October 20-21, the Royal Air Force and France’s Strategic Air Forces conducted Operation Rummy, the first joint Franco-British nuclear air exercise. British Eurofighter Typhoons escorted French Rafales from the Saint-Dizier airbase for a simulated long-range nuclear strike mission. The exercise operationalizes the 2025 Northwood Declaration and demonstrates a British willingness to serve as a conventional enabler for a French nuclear mission, bearing the associated retaliation risks.
Missile Defense as a Complement
NATO Ballistic Missile Defence remains a permanent alliance activity, designed to provide full coverage for European populations against proliferating ballistic missiles. Allies have voiced concerns over the last decade about Iran’s intensified missile tests and the range and precision of its arsenal. Effective missile defense complicates hostile planning and buys leaders time in a crisis, but NATO doctrine holds it can complement—not substitute for—the role of nuclear weapons in deterrence.
Sources
- Deterrence theory
- Nuclear Deterrence Needs to Account for Domestic Politics
- Europeanising NATO: The Nuclear Dimension – International Centre for Defence and Security
- Operation Rummy: Franco-British Nuclear Cooperation Strengthens European Deterrence
- Ballistic missile defence
- US barbarism driving world toward nuclear deterrence: Mokhber
Photo: The White House (Public domain)
