When Nuclear Weapons No Longer Deter

Over the past few weeks, the Middle East has experienced a rapid sequence of developments that have brought the region into a renewed state of uncertainty. Among the most significant were Israeli strikes targeting Iranian sites, followed shortly by U.S. precision airstrikes on three of Iran’s key nuclear-related facilities: the Fordow Fuel Enrichment Plant, the Natanz Nuclear Centre, and the Isfahan Uranium Conversion Facility. These events appear to go beyond isolated military actions. They may signal a broader shift in how deterrence is understood and perceived within the evolving dynamics of regional and international security.

Since the dawn of the nuclear age, international relations theory, particularly the realism school, has conceptualized deterrence as a cornerstone of strategic stability. Realists, such as Kenneth Waltz, have long argued that in an anarchic international system lacking central authority, security is achieved through power, self-help, and, most notably, the credible threat of retaliation. Nuclear weapons, in this framework, represent the apex of deterrent force. Their mere possession, it was believed, would prevent existential threats by imposing unacceptable costs on would-be aggressors.

Yet the Iranian case challenges this orthodoxy.

It is no secret that Iran continues to develop its nuclear program. While Iranian officials assert that the program is intended for peaceful purposes, various international assessments have raised questions about its nature and objectives. Regardless of the real intent, even the perception of nuclear capability carries strategic implications. In theory, such a perception could spark a regional arms race, but more centrally, it is often seen as a means of establishing deterrence.

However, recent developments challenge this assumption. Despite the advancement of its nuclear program, its network of proxies and affiliated non-state actors across the region, and its strategic partnerships with global powers such as Russia and China, Iran was not shielded from military retaliation. Far from functioning as a deterrent, its nuclear posture may have acted as a catalyst, inviting military action rather than preventing it. This case surely invites a deeper examination: Has the traditional logic of deterrence lost its effectiveness, even in asymmetric rivalries, or within an increasingly multipolar context?

The Limits of Nuclear Deterrence

Iran’s failure to deter U.S. and Israeli responses cannot be explained merely by capability gaps. Instead, it reflects structural shifts in how deterrence is perceived and operationalized. Unlike the Cold War bipolar era, where mutual assured destruction (MAD) ensured restraint between superpowers, today’s strategic environment is fragmented, and shaped by a complex array of hybrid threats.

In this landscape, nuclear capability is no longer sufficient unless coupled with credibility, second-strike assurances, reliable alliances, and global legitimacy. Iran, heavily sanctioned, diplomatically and regionally isolated, and lacking a formal nuclear arsenal, does not enjoy these prerequisites. Its deterrent posture is ambiguous and thus ineffective against determined, technologically advanced adversaries.

In the realist view, deterrence hinges as much on perception as on material capabilities. Iran’s nuclear ambitions may have triggered what theorist Stephen Van Evera describes as “preventive war logic,” wherein states strike preemptively to neutralize perceived future threats. Notably, while Israel is widely believed to possess an operational nuclear arsenal and maintains a longstanding policy of nuclear opacity alongside a presumed second-strike capability, Iran has neither declared nuclear weapons nor tested a functioning arsenal and remains under International Atomic Energy Agency (IAEA) safeguards and international scrutiny. In this context, the existence of nuclear programs in both countries, despite their fundamental asymmetry, has not fostered strategic stability or reinforced a regional balance of power. Instead, it may have contributed to greater volatility across the Middle East.

Effective Alliances: The New Determinants of Security?

This brings us to another critical pillar of realist and neorealist thought: alliances. In theory, alliances are instruments of balance, enabling weaker states to bandwagon or balance against stronger ones. Iran has cultivated partnerships with Russia and China, and is increasing its economic relations with India and certain Global South actors. Yet, when the moment of crisis came, these partnerships proved to be more symbolic than strategic.

Comparing this to Israel’s security architecture: deeply embedded in a robust network of Western alliances, NATO, the U.S. strategic umbrella, intelligence cooperation with the Five Eyes, and normalized relations with several Arab states. When Israel is threatened, its allies respond swiftly and comprehensively.

This disparity highlights a critical point: not all alliances and partnerships are equal. Effective security relationships are typically institutionalized, interest-driven, and underpinned by interoperability, shared threat perceptions, and in some cases, formal defense commitments. Iran’s ties with powers such as Russia and China, by contrast, remain largely transactional, shaped by geopolitical alignment, economic expediency, and mutual opposition to Western influence. Although Tehran and Moscow ratified a sort of comprehensive strategic partnership in January 2025, the treaty notably excludes any mutual-defense clause or binding security guarantees. Similarly, Iran’s strategic cooperation agreement with China fosters economic and military-technical collaboration, but lacks formal defense obligations. Consequently, when deterrence falters, these partnerships provide little tangible protection for Iran.

A New Paradigm: Multidimensional Deterrence

What, then, defines deterrence in today’s world?

First, military power alone is insufficient. As Joseph Nye has argued, soft power and smart power, as the ability to shape preferences, influence norms, and build legitimacy, are increasingly essential. Iran’s international image, marred by sponsorship of non-state actors and internal repression, has hindered its ability to marshal global support, unlike Ukraine for example.

Second, multilateralism and institutional alliances matter. NATO’s Article 5 remains one of the most credible deterrents because it reflects the collective security logic and enshrined in treaty law, not in vague diplomatic rhetoric. Iran, in contrast, lacks any formal defense guarantees.

Third, technology and intelligence dominance now rival traditional military power. Advancements in cyber operations, drone warfare, AI-driven surveillance, and intelligence gathering are redefining the contours of strategic balance in contemporary conflict.

From Weapons to Webs of Power

The Iranian case forces a recalibration of the assumptions that deterrence is no longer just about possessing weapons of mass destruction. It is about weaving a dense web of military preparedness, diplomatic legitimacy, strategic alliances, and narrative power.

If Iran’s nuclear ambition has failed to deter, it is not necessarily because nuclear weapons are obsolete, but because deterrence itself has evolved. In the 21st century, states must craft multidimensional strategies that integrate force, foresight, and allies. Anything less may invite not balance but backlash.

Now that the military confrontation with Iran has concluded, there is an opportunity to revisit and reimagine key international concepts in light of current realities. Terms once shaped by earlier geopolitical eras must be adapted to reflect the complexities of today’s context. Especially as the Middle East region begins to absorb the consequences of recent events, this moment calls for a reassessment of strategic priorities and alignments at both regional and international levels. Amid these shifting dynamics, one hope remains: that peace and stability will ultimately prevail, both in the Middle East and beyond.