In a political moment marked by the short but intense 12-day war between Iran and Israel, global attention has been reignited on a mechanism that is at once technical and profoundly political: the so-called “snapback,” the legal and strategic axis of the Joint Comprehensive Plan of Action (JCPOA), signed in 2015 by Iran and the P5+1 — the United States, Russia, China, France and the UK, plus Germany, with the European Union acting as coordinator.
This instrument, incorporated into UN Security Council Resolution 2231 and accepted by Iran and the P5+1, allows for the automatic reimposition of international sanctions in the event of a substantial breach by Tehran.
What was originally conceived as a legal safeguard clause has since been transformed into a point of geopolitical friction, a locus of legal controversy and a reflection of the profound and accelerating reconfiguration of the international order.
The E3 — the UK, France and Germany — has explicitly threatened to reactivate the snapback mechanism, a clear signal that, in their assessment, Iran is committing breaches that would justify reimposing sanctions.
This threat should not be understood as the mere formal suggestion outlined in the JCPOA text, but rather as a strategic tool amid escalating tensions following the war and the collapse of diplomatic dialogue.
The actual activation of the snapback would involve a formal notification to the president of the UN Security Council, based on concrete accusations against Iran, and would trigger a 30-day period during which the council could adopt a resolution to block the reimposition of sanctions.
If no such resolution is issued, it would mean the automatic restoration of the previous sanctions regime, even without the consent of the permanent members.
Snapback origin story
In its formal terms, the snapback functions as a legal valve. Any of the seven JCPOA signatories can denounce a significant breach by Iran. If, within 30 days, the UN Security Council does not adopt a resolution blocking that accusation, the suspended international sanctions would be automatically reactivated.
What is significant is that the mechanism is triggered without the need for explicit consensus and without veto power from the permanent members, reversing the traditional logic of Security Council operations. This singularity makes the snapback an anomalous procedure within contemporary international law.
For decades, the governance of global security rested on the imperfect balance of the veto: no actor could impose sanctions if another blocked them. The JCPOA mechanism was designed to break that institutional paralysis.
Its justification was pragmatic: ensuring Iran could not exploit normative gaps or divisions among the powers. But the price of that innovation was introducing an exception that altered the basic rules of multilateralism. Today, that alteration is a central point of litigation.
The snapback has generated major interpretative controversy. Iran maintains that the US’ unilateral exit in 2018 nullified its legitimacy to invoke the mechanism. By formally withdrawing from the JCPOA, Washington lost its status as an active party and thus any derived rights.
The Iranian position rests on consent: international treaties and their associated regulations depend on effective and voluntary participation. A state that withdraws from its adherence forfeits the privileges that come with it. The opposing view, defended by the US and supported by the E3, holds that the right to activate the snapback persists regardless of formal membership in the agreement.
This position is justified by the need to ensure that Iran remains under strict oversight. Its proponents argue that giving up this right would create a global security vacuum. According to this interpretation, the control mechanisms tied to Resolution 2231 have an independent character that transcends the political fate of the JCPOA.
The dispute is more than legal: it reveals two opposing visions of how the international order functions. For Tehran and its allies, such as China and Russia, law is the product of a pact, and breaking that pact invalidates it. For Washington and its partners, law can persist beyond consent, especially when upheld under collective security interests.
Law as instrument of power
The mechanism exposes a structural tension: international law has never been an autonomous zone of norms, but rather a stage where power dynamics play out. The snapback underscores that tension, for a rule meant to ensure predictability becomes a lever of confrontation.
From the Iranian perspective, reactivating the snapback in the absence of consensus — and under the pressure of a party that has already withdrawn — is viewed as an example of abuse of law.
This notion, central to classical international law, refers to using legal provisions to gain unforeseen or unjustified advantages. Here, the abuse appears as an attempt to impose normative hegemony disguised as judicial authority.
This raises a crucial question: how is legitimacy rebuilt in an order where norms are wielded as strategic levers? For Iran, the immediate consequence is the questioning of sovereign equality. Experiencing law as selective coercion, Iranian discourse concludes that international law no longer represents a common framework — but an instrument shaped by the powerful.
The controversy over the snapback has deepened divisions within the Security Council. Russia and China oppose its reactivation and question the legality of the U.S. position. Both insist that the loss of consensus makes automatic application unworkable. Beyond Iran, their argument reflects a broader principle: resisting the use of multilateral institutions as extensions of Western power.
The E3, by contrast, maintains the mechanism as a last resort to prevent Iran from nearing full nuclear capability. Europe plays a dual role: preserving a minimal functional global order while preventing total collapse of the JCPOA, even if its real authority is nearly spent.
The confrontation thus pits those defending a disciplinary backstop even in fractured consensus against those favoring adherence to procedural rules, even if it means abandoning the mechanism.
The rest of the world watches with interest and caution. Several Global South countries see this as confirmation of a recurrent narrative: international law is applied unevenly, imposed on some but softened for others. In this light, the snapback against Iran contrasts strongly with the relative impunity of states wielding vetoes or commanding military power.
Iran’s political snapback
The international dispute resonates within Iranian politics. Since the JCPOA was signed under President Hassan Rouhani and Foreign Minister Javad Zarif, the split in domestic politics has persisted between opening-deal supporters and principlist hardliners who saw the agreement as an excessive concession to Western powers.
The US withdrawal in 2018 bolstered the latter camp, reinforcing their view that the West would not guarantee reciprocity or legal stability.
By 2025, under President Masoud Pezeshkian’s government, that split remains active. Parliament has passed a law ending cooperation with the International Atomic Energy Agency (IAEA). Even so, the executive seeks to preserve legal channels for continuing dialogue with the IAEA, aware that total rupture would deepen Iran’s isolation.
This dual logic — parliamentary pressure and governmental pragmatism — shapes Iran’s stance: asserting sovereignty and condemning arbitrariness, while not fully closing technical channels. For the government, the challenge is maintaining room for maneuver amid internal pressures, external demands, and an economy weakened by sanctions.
Beyond the immediate context, Tehran views the snapback as symbolic of a global transition. What’s at stake is not merely a nuclear mechanism but the image of an international order that no longer rests on broad consensus or stable rules. Law is perceived less as a universal structure and more as a contested space where actors reinterpret meaning according to power.
The snapback’s uniqueness — its automatic procedure that bypasses vetoes — makes it a powerful metaphor for this tension. An instrument conceived to ensure stability ends up generating instability. A rule intended to overcome deadlock becomes an obstacle to systemic cohesion. The mechanism embodies the constitutive contradiction of the international order: the aspiration for universality coexisting with immutable hierarchies.
The heart of the dispute is not only Iran’s compliance but the absence of a recognized authority capable of judging activation legitimacy. Ideally, the Security Council would play that role. But, as it stands, the council is fractured: it has become a stage for rivalries rather than a forum for adjudication. As a result, each party wields partial interpretations that postpone resolution.
Iran frames this fragmentation as proof that international legality is relative and dependent on enforcement power. The US and Europe counter that the mechanism’s exceptional nature justifies its use even without consensus, under the rationale of prevention and collective security. The absence of agreement doesn’t paralyze the system — it turns it into a constant battleground.
Between sovereignty, law and power
The debate over the snapback underscores the impossibility of separating norm from politics, law from hegemony. Iran’s stance is pragmatic, not ideological: defending sovereignty within a system it deems biased while preserving technical channels.
For the US and Europe, the mechanism functions as control, even at the cost of eroding legitimacy. For Russia, China and much of the Global South, the crisis affirms the partiality of the prevailing order.
At this crossroads, Iran finds itself in a pivotal role not by choice but because its case encapsulates the elements of the global crisis: regional conflict and systemic division in the international order. The snapback is no longer a technical detail but a symbol of ongoing disputes about sovereignty, legitimacy and global governance.
Stakes today extend beyond Iran’s nuclear program to the future of an international legal order suspended between universal aspiration and dependence on power. To speak of snapback is to speak of the attempt to uphold an order whose foundations are eroding.
The near future — heavy with uncertainty — hinges on whether the mechanism solidifies into an effective and just tool or collapses into a reminder of the system’s incoherence.
Xavier Villar (PhD) is a Spanish national based in Iran. His research and analysis focuses primarily on Iranian politics, regional dynamics, and the shifting architecture of the international order.