KEY TAKEAWAYS
- The myth of absolute deterrence: Nuclear weapons have long been considered the ultimate safeguard against war, but current conflicts reveal that possession does not equate to political immunity or strategic stability.
- Russia–Ukraine: Despite owning the world’s largest nuclear arsenal, Russia’s deterrent failed to prevent NATO involvement, drone strikes on Moscow, long-range missile threats, or Ukrainian incursions into its territory. Nuclear threats have lost credibility through overuse.
- Israel–Gaza: Israel’s nuclear status did not deter Hamas’s 7 October 2023 attacks, nor subsequent hostilities from Hezbollah and the Houthis. Nuclear weapons are ineffective against non-state actors and asymmetric warfare.
- Israel–Iran: Both states’ deterrence models were questioned in the June 2025 “Twelve-Day War.” Israel’s arsenal and Iran’s latent nuclear capacity failed to prevent open conflict, showing that political imperatives can override deterrent logic.
- India–Pakistan: Two nuclear-armed powers engaged in conventional war in 2025, confirming that nuclear parity restrains escalation but cannot prevent warfare.
- Nuclear weapons remain a shield against annihilation but no longer function as instruments of absolute deterrence. The Cold War’s faith in deterrence requires urgent re-evaluation in a multipolar world.
Since 1945, the possession of nuclear weapons has been imagined as the ultimate guarantor of security. Nuclear deterrence theory, developed during the Cold War, held that once a state possessed a credible nuclear arsenal, the risks of catastrophic retaliation would render major war unthinkable. This “nuclear peace” thesis, advanced by scholars such as Kenneth Waltz, Bernard Brodie, and Thomas Schelling, treated the bomb as the great equaliser: it froze conflicts, enforced caution, and created an equilibrium of fear.
From the doctrine of Mutual Assured Destruction (MAD) between the United States and the Soviet Union to the regional deterrence systems of South Asia and the Middle East, nuclear possession has been elevated to an orthodoxy in strategic thought. To possess the bomb was to possess political immortality; to lack it was to risk existential defeat.
Yet the twenty-first century, and especially the years 2022 to 2025, have profoundly unsettled this received wisdom. Across multiple theatres (Ukraine, Israel and Gaza, Iran, and South Asia), the supposed shield of nuclear deterrence has failed to prevent escalation, proxy war, or even direct interstate conflict. The myth of the nuclear “Holy Grail” now collides with a sobering reality: nuclear weapons, while preventing annihilation, do not necessarily guarantee restraint or stability.
Russia–Ukraine
Russia possesses the largest nuclear arsenal on earth. Its strategic triad, numbering thousands of warheads, was presumed to make any direct challenge by NATO inconceivable. Yet, since its full-scale invasion of Ukraine in February 2022, Moscow has found that nuclear power no longer translates neatly into political leverage.
As U.S. Secretary of State Marco Rubio effectively described it in January 2025, the war has become a three-year-long proxy war between the USA/NATO and the Russian Federation. Despite frequent nuclear signalling, including Russian references to “all available means,” the deployment of tactical weapons in Belarus, and exercises by Russia’s Strategic Rocket Forces, Western states have progressively tested and crossed Moscow’s proverbial red lines.
Ukraine has struck deep within pre-war Russian territory; drones have reached military installations and even Moscow’s Kremlin itself. NATO-supplied long-range systems, once considered escalatory, are now routinely employed. Russia’s nuclear deterrent has therefore failed to deter either the erosion of what Russia considers its geopolitical buffer zones or the material encroachment on its territory. The deterrent’s political potency has been hollowed out by credibility fatigue: the more often a nuclear threat is issued without consequence, the less it deters. Russia has confronted the limits of nuclear deterrence and the realisation that even overwhelming nuclear capability does not ensure absolute political or strategic security. Its failure to halt NATO’s expansion or the Ukrainian counter-offensive underscores the obsolescence of the Cold War belief that nuclear weapons neutralise conventional vulnerability. On the contrary, the war has reaffirmed the enduring importance of conventional power, logistics, industrial resilience, and boots on the ground.
Israel–Gaza
Israel, the Middle East’s sole nuclear-armed state, epitomised deterrence orthodoxy for decades. Its undeclared but widely acknowledged nuclear arsenal was meant to dissuade existential threats from hostile neighbours. Yet, the events of 7 October 2023, when Hamas launched a massive cross-border attack killing over a thousand Israelis and taking hundreds hostage, shattered the illusion of absolute security.
Neither the knowledge of Israel’s nuclear capability nor its overwhelming conventional strength deterred Hamas, Hezbollah, Iran’s True Promise I & II operations, or the Houthis from escalating regional confrontation. Israel’s nuclear deterrent was irrelevant to sub-state actors driven by ideology, martyrdom, and asymmetric warfare. Nuclear weapons, being instruments of annihilation, are useless against non-state adversaries operating from within densely populated civilian zones.
The failure here is twofold. Strategically, Israel’s nuclear deterrent did not prevent attacks that triggered a prolonged war in Gaza and widespread regional instability. Politically, it has exposed the moral and practical limitations of relying on the bomb for existential reassurance. As in the Russian Federation, the nuclear arsenal did not translate into strategic immunity; instead, it coexisted with acute vulnerability. The Israel–Gaza case underscores a broader erosion of the nuclear taboo and the emergence of questioning the political uses of nuclear weapons in preventing or managing conventional wars.
Israel–Iran
If Israel’s nuclear capability has failed to deter non-state actors, its confrontation with Iran reveals the limitations of deterrence even between states. Iran, while not possessing nuclear weapons, has pursued a deliberate policy of “nuclear latency,” maintaining the capacity to produce a weapon without crossing the threshold (described in 2012 by Kenneth Waltz as one of Iran’s possible strategies going forward). This latent capability was meant to deter Israeli or American aggression by projecting the potential for nuclear breakout.
Yet, in the so-called “Twelve-Day War” of June 2025, deterrence collapsed on both sides. Israel initiated a war against the Islamic Republic, PR-packaged as pre-emptive strikes against Iranian nuclear and military facilities, arguing that Tehran’s proxies and missile programmes posed an intolerable threat. Iran responded with direct missile and drone attacks on Israeli territory, including hypersonic missiles, inflicting significant damage despite Israel’s Iron Dome, Arrow, THAAD, and David’s Sling defences.
Here, neither Israel’s nuclear deterrent nor Iran’s nuclear policy prevented conflict. This mutual negation of deterrence points to a deeper truth: the myth, taboo, and doctrine of nuclear deterrence absolutism have replaced empirical reality as it unfolds on the ground in 2025. There exists no historical precedent of surrender purely due to nuclear threat or strike; Hiroshima and Nagasaki were mythologised into an American narrative of decisive atomic victory, yet Japan’s surrender may be read thus only via a posteriori historiographical lens. (Readers interested in exploring this further may consult, e.g., Yukiko Koshiro’s book Imperial Eclipse: Japan’s Strategic Thinking About Continental Asia Before August 1945).
India–Pakistan
Furthermore, when India and Pakistan conducted their nuclear tests in 1998, many analysts argued that the subcontinent had entered a new era of stability. Kenneth Waltz’s optimists believed that nuclear parity would impose caution, and for two decades, despite periodic crises, the two rivals avoided full-scale war.
That assumption collapsed in 2025, when border clashes in Kashmir escalated into a major interstate conflict. Both sides, though nuclear-armed, engaged in sustained conventional hostilities. For weeks, analysts feared escalation, potentially even up to the nuclear threshold should things turn awry, yet neither did this transpire, nor was the war averted in the first place. The war demonstrated that deterrence can restrain escalation but not prevent war itself.
In essence, nuclear weapons in South Asia have become tools of psychological reassurance rather than practical deterrence. Their presence allows leaders to act more boldly at the conventional level, assuming that nuclear escalation remains improbable. This phenomenon, sometimes called the “stability–instability paradox,” renders deterrence self-defeating: by preventing total war, it paradoxically enables limited war.
Reassessing the limits of nuclear deterrence
Across these theatres, a common pattern emerges: the decoupling of nuclear capability from political influence. Possessing the bomb no longer confers automatic, much less absolute, deterrence, nor does it guarantee stability. The Cold War’s nuclear orthodoxy, rooted in bipolar rationality, superpower control, and the MAD doctrine, has fractured in a multipolar, hybrid-conflict world.
Recent scholarship underscores that the erosion of deterrence is not merely empirical but structural. Vipin Narang (2017) has shown that states’ nuclear postures, whether assured retaliation, catalytic, or asymmetric escalation, profoundly shape the credibility and flexibility of deterrence, suggesting that posture diversity itself can generate instability. Matthew Kroenig (2020) similarly argues that the return of great-power nuclear competition is reviving Cold War–era coercive dynamics in a more multipolar context, eroding predictability and crisis stability. Complementing these strategic insights, Nina Tannenwald (2018) documents the gradual weakening of the nuclear taboo, as both rhetoric and policy have normalised discussions of nuclear use once deemed unthinkable. Lawrence Freedman (2019), meanwhile, cautions that deterrence ultimately rests on the credibility of signalling and communication, which, in contemporary conflicts, is increasingly undermined by ambiguity, disinformation, and the diffusion of power. Together, these perspectives reinforce the argument that nuclear deterrence’s apparent decline reflects not simply changing behaviour but a systemic transformation of how states understand and perform nuclear restraint.
Three insights deserve emphasis here. First, the myth: the belief that nuclear weapons compel submission or guarantee peace lacks historical foundation. Second, the taboo: the moral inhibition against nuclear use, once sacrosanct, is weakening as nuclear rhetoric becomes normalised. It is exceedingly difficult to imagine a scenario in which, throughout the totality of human history, such weapons would have only been used twice in the atomic bombings of Hiroshima and Nagasaki in 1945. Third, the doctrine: MAD itself is being relativised; strategic ambiguity and limited wars between or around nuclear states are increasingly possible.
Nuclear deterrence has not vanished, but it has failed in its absolute claim to prevent war. In Russia’s challenged deterrence, Israel’s vulnerability, Iran’s nuclear policy choices, and South Asia’s instability, the bomb has proven to be an inert god: worshipped, feared, but politically anything but omnipotent.
As the international system slides toward renewed great-power rivalry and regional militarisation, policymakers and scholars alike must soberly reassess the limits of nuclear deterrence, since its promise of near-absolute security borders on the illusory.
* Dimitris B. Peponis is the author of The End of the Great Deviation: From Ukraine and the Pandemic to the Shaping of the New Global Order (Topos books, in Greek).
* Sotiris Mitralexis holds a doctorate in political science and international relations; he is an Honorary Senior Research Fellow at University College London.