Ceasefire Without Peace: Escalation, Legality, and the Collapse of Non-Proliferation in the Israel–United States–Iran Conflict

The essay argues that the 2026 war was the predictable endpoint of a coercion-only strategy pursued since the 2018 JCPOA withdrawal, with force twice deployed mid-negotiation in breach of the UN Charter. The campaign proved self-defeating: it consolidated the regime, left the nuclear programme unmon

Introduction

The confrontation between Israel, the United States, and the Islamic Republic of Iran has, over the past decade, evolved from a contest of sanctions, sabotage, and proxy warfare into direct interstate war. The Twelve-Day War of June 2025, in which Israel and subsequently the United States struck Iranian nuclear and military infrastructure, was widely treated at the time as a watershed (Congressional Research Service, 2026a). It was, in retrospect, only a prelude. On 28 Feblocal-section-mainruary 2026, the United States and Israel launched a far larger campaign against Iran, killing Supreme Leader Ali Khamenei on its opening day and triggering more than five weeks of regional war, a crisis in the Strait of Hormuz, the resumption of full-scale conflict in Lebanon, and the most consequential breakdown of the non-proliferation regime since its creation (House of Commons Library, 2026a; Britannica, 2026).

This essay analyses the conflict critically rather than descriptively. It advances three interrelated arguments. First, the war of 2026 was not an aberration but the predictable terminus of a coercive strategy, pursued since the American withdrawal from the Joint Comprehensive Plan of Action (JCPOA) in 2018, that systematically devalued diplomacy while underestimating the limits of military force. Second, the legal justifications offered for the February 2026 attack, launched during active negotiations and aimed explicitly at regime change, fail under any defensible reading of the United Nations Charter, and the precedent set is corrosive to the international legal order in ways that will outlast the war itself. Third, the conflict demonstrates a paradox familiar to students of non-proliferation: military action intended to prevent nuclear weapons acquisition has strengthened, not weakened, the strategic logic of proliferation, both in Tehran and among observers elsewhere. The essay proceeds chronologically and thematically: it first reconstructs the structural background, then examines the 2025 war and the collapse of the diplomatic track, before turning to the 2026 war, its legality, the Pakistan-mediated ceasefire, and the conflict’s wider implications for peace and security.

The Structural Background: Maximum Pressure and Its Discontents

Any serious analysis must begin with the JCPOA and its destruction. The 2015 agreement, endorsed by United Nations Security Council Resolution 2231, traded verifiable restrictions on Iran’s nuclear programme for sanctions relief. Its central achievement was technical rather than political: it extended Iran’s “breakout time” to roughly a year and subjected the programme to the most intrusive inspection regime ever negotiated (Davenport, 2023). The unilateral American withdrawal in May 2018, under the first Trump administration, replaced this bargain with “maximum pressure”, a strategy premised on the assumption that economic strangulation would compel Iranian capitulation or regime collapse.

The empirical record of maximum pressure is, on its own terms, one of failure. Iran responded not with capitulation but with calibrated escalation: from 2019 it progressively exceeded JCPOA limits, and from February 2021 it ceased implementing its JCPOA-specific commitments altogether, while the International Atomic Energy Agency (IAEA) retained only the narrower verification rights afforded by Iran’s Non-Proliferation Treaty (NPT) safeguards agreement (United Nations, 2025). By 2025 Iran had accumulated a substantial stockpile of uranium enriched to 60 per cent, a level with no plausible civilian application, placing it weeks rather than months from weapons-grade material. The strategy thus produced precisely the outcome it claimed to prevent: an Iran closer to the bomb than at any point under the JCPOA, with diminished international oversight and hardened domestic politics. This is not a marginal critique. It is the analytical foundation for understanding why, by 2025, both Washington and Jerusalem confronted a problem that their own prior choices had made acute, and why they reached for force.

Simultaneously, the regional balance shifted dramatically after October 2023. The degradation of Hamas, the decimation of Hezbollah’s leadership and arsenal in 2024, the fall of the Assad government in Syria, and the direct Iranian-Israeli missile exchanges of April and October 2024 stripped away the forward-defence architecture on which Iranian deterrence had rested for four decades (International Crisis Group, 2025). Iran entered 2025 strategically exposed, economically weakened, and internally contested. From a realist perspective, this asymmetry created a classic window-of-opportunity logic in Israeli and American planning; from a peace research perspective, it created the conditions under which the stronger parties’ incentives to negotiate seriously collapsed, since coercion appeared cheaper than compromise (cf. Zartman, 2001, on ripeness and its absence).

The Twelve-Day War and the Politics of “Obliteration”

Israel’s strikes of 13 June 2025, launched days before a planned sixth round of American-Iranian nuclear talks, and the American attack on the Fordow, Natanz, and Isfahan facilities on 22 June, tested the proposition that proliferation can be bombed away (Deccan Herald, 2025). The honest answer, visible within months, was that it cannot. Three findings support this claim.

First, the strikes destroyed infrastructure but not material or knowledge. The IAEA reported in October 2025 that it had no information on the status of Iran’s enriched uranium stockpiles, an extraordinary admission that the highly enriched uranium accumulated before the war was effectively unaccounted for (United Nations, 2025). The strikes therefore converted a monitored programme into an unmonitored one. Second, Iran responded by blocking inspections of the damaged sites, and its parliament moved to restrict IAEA access by statute, with senior figures openly debating NPT withdrawal (INSS, 2025; NCRI, 2025). Third, the war destroyed what remained of the diplomatic track’s credibility inside Iran. Negotiators who had argued that engagement could protect Iran from attack were discredited by the fact that attack arrived mid-negotiation. The lesson institutionalised in Tehran was that diplomacy invites vulnerability, a lesson that would be taught a second time, more brutally, in February 2026.

The European response compounded the spiral. On 28 August 2025 France, Germany, and the United Kingdom invoked the “snapback” mechanism of Resolution 2231, and United Nations sanctions were reimposed on 27 September 2025 after the Security Council failed to adopt either a relief-extension resolution or a Russian-Chinese compromise extending the JCPOA framework to April 2026 (Congressional Research Service, 2026b; Security Council Report, 2025). The legality of snapback was itself contested: Iran argued that the E3 had forfeited participant status through their own non-performance, Russia argued the dispute-resolution process had not been exhausted, and several Council members rejected the measure as procedurally flawed (Security Council Report, 2025; United Nations, 2025). Whatever the doctrinal merits, the political effect was unambiguous. Snapback was imposed at the moment of Iran’s maximum post-war insecurity, demanded transparency that Iran regarded as its last bargaining asset, and offered no security guarantee in exchange (Foreign Policy, 2025). It is difficult to construct a sequence better designed to confirm hard-line Iranian assumptions, and the November 2025 IAEA Board resolution, followed by Iranian threats of NPT withdrawal and rhetorical flirtation with “imported” warheads, completed the deterioration (NCRI, 2025).

A critical observation is warranted here. Western commentary tended to frame each Iranian step, reduced cooperation, legislative restrictions on the IAEA, withdrawal threats, as evidence of bad faith requiring further pressure. Yet sequence matters analytically. Each Iranian measure followed, rather than preceded, a coercive Western or Israeli action: strikes, snapback, censure. This does not exculpate Tehran, whose enrichment to 60 per cent lacked civilian justification and whose obstruction of safeguards violated binding obligations. But it does indicate a security dilemma in near-textbook form (Jervis, 1978): measures each side took to enhance its security systematically diminished the security of the other, and third-party institutions, the Security Council and the IAEA, were conscripted into the coercive apparatus rather than functioning as circuit-breakers.

The 2026 War: Decapitation During Negotiation

The February 2026 talks, mediated by Oman, were by the mediator’s own account substantively promising. Oman’s foreign minister stated publicly that progress had been substantial and that Iran had newly committed never to possess weapons-usable nuclear material (House of Commons Library, 2026b). The American and Israeli strikes began the following day, 28 February 2026, killing Supreme Leader Khamenei and numerous senior officials in the opening salvo, with the stated aims of inducing regime change and destroying Iran’s nuclear and ballistic missile programmes (House of Commons Library, 2026a; Wikipedia, 2026a).

The war that followed, sometimes termed the Third Gulf War, was an order of magnitude larger than 2025. Iran retaliated with hundreds of ballistic missiles and thousands of drones against Israel, American bases, and Gulf Arab states, including a strike on a Saudi petrochemical facility that nearly destroyed mediation efforts; the conflict reignited the Israel-Hezbollah war, displacing over one-sixth of Lebanon’s population; thousands died in Iran and Lebanon, dozens in Israel and the Gulf; and traffic through the Strait of Hormuz, through which roughly a fifth of global oil transits, was severely disrupted (Britannica, 2026; Al Jazeera, 2026a). Internally, the assassination of Khamenei, who was succeeded by his son, produced not collapse but a contested consolidation, with security forces suppressing both celebration and dissent in a population already brutalised by the massacres of January 2026, when the regime killed thousands during the largest protests since 1979 (Wikipedia, 2026a; Britannica, 2026).

Three critical judgements follow.

The legality of the attack is indefensible. Article 2(4) of the UN Charter prohibits the use of force against the territorial integrity or political independence of any state; Article 51 permits self-defence against armed attack, which a body of state practice and the Caroline criteria extend, at most, to imminent attack. No claim of imminence was credible in February 2026. Iran’s nuclear programme, however alarming, constituted a latent capability, not an armed attack; the targets included the head of state and the machinery of government; and the declared objective was regime change, which the Charter’s drafters specifically intended Article 2(4)’s reference to “political independence” to foreclose. Iran’s characterisation of the strikes as a breach of the Charter (House of Commons Library, 2026a) is, on this point, simply correct, and the discomfort this causes Western legal scholars should not be elided. The 2026 war extends the “preventive war” logic of Iraq 2003 to its limit case: force used against a state during negotiations, on the basis of capabilities rather than acts, to destroy its government. If this precedent stands, the prohibition on force becomes a privilege of the weak rather than a rule binding the strong, a development that states from Beijing to Brasília have already registered.

The strategic theory of victory was incoherent. Decapitation strategies presume that removing leadership produces either collapse or a more pliant successor. The empirical literature on leadership targeting offers little support for this in consolidated authoritarian systems, where succession mechanisms exist precisely to absorb such shocks (Jordan, 2014). So it proved: the Islamic Republic survived its founder’s successor’s death, the succession was managed within weeks, and the regime’s narrative of encirclement was vindicated before its own population at the very moment, weeks after the January massacres, when its domestic legitimacy was most fragile. The war thus arguably rescued the regime from its gravest internal crisis since 1979 by externalising it. Equally, the proposition that the nuclear programme could be ended by force had already been falsified in 2025; repeating the experiment at greater scale destroyed more buildings while leaving the fissile material unaccounted for and the knowledge intact (cf. Foreign Policy, 2025, on the impossibility of erasing nuclear knowledge through strikes).

The humanitarian and regional costs were borne overwhelmingly by third parties. Lebanon, which initiated nothing, suffered nearly 1,500 deaths and mass displacement after Hezbollah entered the war citing Khamenei’s killing and prior ceasefire violations (Al Jazeera, 2026a). Gulf states absorbed Iranian retaliation for decisions taken in Washington and Jerusalem. The pattern, in which the costs of great-power and Israeli-Iranian confrontation are externalised onto weaker regional societies, is a structural feature of this conflict that purely state-centric analysis obscures, and it explains the conspicuous reluctance of Arab governments to endorse the campaign despite their long-standing antipathy to Iranian power.

Ceasefire Without Peace: The Islamabad Process

The war’s diplomatic endgame is as analytically revealing as its conduct. The conditional ceasefire announced on 8 April 2026 was brokered not by the United Nations, not by the European Union, and not by Oman or Qatar, but by Pakistan, with Chinese pressure reportedly decisive in securing Khamenei’s successor’s approval, and it materialised hours before an American ultimatum to destroy Iranian bridges and power plants (Britannica, 2026; Congressional Research Service, 2026a; Reuters, 2026). The Islamabad Talks of 11-12 April brought Vice President Vance into direct negotiation with parliament speaker Ghalibaf, the highest-level direct American-Iranian engagement since 1979, and produced agreement on most elements of Iran’s ten-point plan, but collapsed on the two questions that matter most: the nuclear programme and the Strait of Hormuz (Wikipedia, 2026b; Congressional Research Service, 2026a). The American response to diplomatic failure was a naval blockade of Iranian shipping, an act which is itself, in classical international law, an act of war (Congressional Research Service, 2026a).

Several features of this process merit critical attention. First, no agreed ceasefire text was ever published, and the parties’ divergent public characterisations guaranteed recurring violations, culminating in the June 2026 exchanges in which Israeli strikes on southern Beirut triggered Iranian missile salvos, an American helicopter was downed, and the United States struck Iran again on 9 June before both sides once more suspended operations (CNN, 2026a; Britannica, 2026). A ceasefire without text, monitoring, or third-party verification is less an agreement than a synchronised pause, and the peace research literature is unequivocal that such arrangements have high failure rates absent institutionalisation (Fortna, 2004). Second, the linkage problem is structural: Iran conditions its restraint on an end to Israeli operations against Hezbollah, Israel refuses any such linkage, and Hezbollah itself rejected the Lebanese-Israeli ceasefire terms as surrender (CNN, 2026b). The conflict is thus a system of interlocking dyads in which any single bilateral ceasefire can be detonated by a third party, a configuration that mediators have so far addressed sequentially rather than holistically.

Third, the economics of the confrontation deserve more weight than they typically receive. The Strait of Hormuz dimension transformed a regional war into a global one: severe disruption of the world’s most important oil chokepoint imposed costs on energy importers in Asia, Africa, and Europe that had no voice in the decisions producing them, and it is precisely this externality that gave Beijing both the motive and the leverage to press Tehran toward the April ceasefire (Britannica, 2026). The subsequent American naval blockade, announced after the Islamabad Talks failed, attempts to weaponise the same maritime geography in reverse. Yet blockades are blunt instruments with long historical records of strengthening besieged regimes’ control over scarce resources while immiserating populations, a dynamic painfully familiar from the Iraq sanctions experience of the 1990s. An Iranian economy already battered by snapback sanctions, war damage to energy infrastructure, and the crisis that triggered the protests of early 2026 is now subject to a measure that punishes the society for the state’s intransigence, with predictable consequences for the very social forces that Western policy nominally champions. The contradiction is rarely acknowledged: a strategy that simultaneously seeks to empower the Iranian population against the regime and to impoverish that population through collective economic punishment is working against itself.

Fourth, and most significantly for the study of international order, the mediation geography has shifted. That Pakistan, with Chinese backing, succeeded where Western and Gulf intermediaries failed reflects both Iran’s distrust of any actor aligned with Washington and the emergence of non-Western conflict management as a serious phenomenon rather than a rhetorical aspiration. Trita Parsi’s observation that the failed use of American force has blunted the credibility of American threats while shifting the diplomatic terrain (Al Jazeera, 2026b) captures a broader point: coercive diplomacy depends, in Alexander George’s (1991) classic formulation, on the credible combination of threat and assurance. Washington in 2026 possesses abundant threat and no assurance whatsoever to offer. Having attacked Iran during negotiations twice in nine months, the United States cannot credibly promise that restraint will be reciprocated, and Iranian negotiators say as much, conditioning engagement on evidence of American sincerity (CNN, 2026a). The deficit is not rhetorical but structural, and no mediator can manufacture credibility that the principal has destroyed.

Proliferation, Order, and the Lessons Learned by Others

The conflict’s deepest consequences are likely to be normative and systemic. Three deserve emphasis.

First, the non-proliferation regime has been damaged from both directions. Iran has blocked inspections since June 2025, voided the Cairo Understanding with the IAEA, and openly debates NPT withdrawal (NCRI, 2025; INSS, 2025). But the regime’s custodians have also undermined it: states under IAEA safeguards were attacked over a programme that the agency was still monitoring, and snapback converted the Security Council from arbiter into instrument. The lesson available to any middle power observing this sequence is brutal in its clarity. States that abandoned nuclear weapons or remained transparent (Libya, Ukraine, JCPOA-era Iran) were attacked or invaded; states that crossed the threshold (North Korea) were not. The 2025-2026 wars are, on this reading, the strongest advertisement for nuclear weapons acquisition since 1945, an outcome diametrically opposed to their stated purpose. Scott Sagan’s (1996) insight that proliferation decisions are driven substantially by security models holds: the security model now on display teaches that latency invites attack and only deterrence purchases safety.

Second, the prohibition on the use of force has been further hollowed. The February 2026 attack drew condemnation across the Global South precisely because it compounded the Iraq precedent: preventive war, this time openly coupled with assassination of a head of state and a regime-change objective. Western states’ capacity to invoke the Charter against Russian aggression in Ukraine has been correspondingly diminished, not because the legal arguments are symmetrical, they are not, but because the political economy of norm enforcement depends on consistency that has now been conspicuously abandoned. International order is not self-executing; it is reproduced through practice, and the practice of its most powerful proponents in 2026 has been to treat it as optional.

Third, the war has accelerated multipolar realignment. China’s role in securing the ceasefire, Russia’s and China’s joint contestation of snapback’s validity (Congressional Research Service, 2026b), Pakistan’s emergence as mediator, and Gulf states’ hedging all indicate that the regional security architecture is no longer an American monopoly. Whether this produces stability through balance or instability through fragmentation remains open, but the unipolar assumption embedded in both Israeli and American strategy, that escalation dominance guarantees favourable outcomes, has been visibly eroded by Iran’s demonstrated capacity to impose costs through Hormuz, through missiles, and through partners, even from a position of profound weakness.

Conclusion

The Israel-United States-Iran conflict of 2025-2026 is best understood not as a bolt from the blue but as the cumulative product of strategic choices: the destruction of a functioning arms-control agreement in 2018; a coercion-only strategy that foreclosed assurance; the resort to force against a monitored nuclear programme in 2025; the legally indefensible decapitation campaign of 2026, launched during negotiations it rendered retrospectively naive; and a ceasefire process that has paused violence without addressing any of its drivers. At each juncture, decision-makers in Washington and Jerusalem privileged the demonstration of resolve over the construction of restraint, and at each juncture the result was an Iran less monitored, less constrained, and more convinced that only deterrent capability guarantees survival, alongside a region more militarised and an international legal order more openly contingent on power.

This essay has argued that the conflict’s central paradox is self-defeat: military force deployed to prevent proliferation has incentivised it; regime-change strikes intended to topple the Islamic Republic consolidated it at its weakest moment; and coercive diplomacy practised without credible assurance has destroyed the trust on which any durable settlement depends. None of this absolves Tehran, whose enrichment trajectory, regional militarism, and massacre of its own citizens in January 2026 are matters of record. But a critical analysis must resist the comfortable symmetry of “both sides” framing where the evidence indicates asymmetry of initiative: in 2018, 2025, and 2026, it was Washington and Jerusalem that chose escalation at moments when diplomatic alternatives demonstrably existed.

For the study of peace and development, the case is sobering. It demonstrates the fragility of negotiated non-proliferation when great powers treat agreements as revocable; the limits of military instruments against knowledge-based capabilities; the externalisation of conflict costs onto third societies, above all Lebanon’s; and the migration of effective mediation away from Western institutions. The fragile ceasefire of mid-2026, violated within weeks of every renewal, will hold only if it is converted into an institutionalised process addressing the nuclear question, regional security, and sanctions simultaneously, with guarantees credible to a state that has twice been attacked mid-negotiation. The probability of such a conversion under current leaderships is low. The alternative, a region in which a humiliated, unmonitored Iran races for the deterrent its adversaries’ actions have taught it to need, is the legacy that the wars of 2025 and 2026 have made most likely.

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