On Violence: Self-Defence to Self-Determination in International Law

There are moments when the international legal order reveals itself not through its rules but through the violence done in its name. Today’s expanding doctrine of self-defence—invoked with increasing ease, justified with decreasing care—is one such moment. It is tempting to read this as an unravelling, a slide into disorder. Yet what is unravelling here is not only the legal threshold for self-defence, but the authority of states to render violence intelligible as lawful at all. As Hannah Arendt reminds us, violence can destroy power, but it cannot create it. And as Frantz Fanon teaches, disorder is not always destructive; it can also be generative of new forms of normative legibility within law.  Sometimes, it is the only language left for those whom the “order” was never meant to protect.

In this piece, I want to think with both of them about the erosion of authoritative legal meaning and the search for its alternatives. I will focus on the transformation of self-defence as a limiting norm, and self-determination as a competing site of legal meaning-making. Rather than conceiving these doctrines as separate and unrelated, I argue that they are structurally entangled within a shared crisis of legal authority: as self-defence loses its capacity to limit violence, self-determination emerges as an alternative site to contest its meaning.

When a good offence becomes self-defence

Recent armed attacks by the United States and Israel in Iran have intensified debate over the doctrine of self-defence. Despite widespread doubt that the legal threshold has been met, officials have justified US Operation Epic Fury on defensive grounds invoking imminence, necessity and long-standing threat narratives. In perhaps the boldest justification to date, Pete Hegseth has framed the strikes as defensive, yet in doing so advances an expansive view in which, as he puts it, ‘the best defence is a good offence’.

In one register, these arguments might be understood as anomalous within an otherwise coherent framework governing the use of force under the UN Charter and customary international law. Since the end of the Cold War, states have invoked self-defence across a wide range of contexts—from Kuwait to Afghanistan and Iraq, to Syria and beyond—while the Security Council has authorised force under Chapter VII, including in Libya, under the controversial Responsibility to Protect. On this view, even more controversial doctrines such as ‘unwilling or unable’ form part of a recognisable normative framework which may amount to customary international law.

Yet viewed in another register, these developments are not anomalous at all. They represent the culmination of a decades-long erosion of self-defence as a limiting norm, transforming it into an increasingly permissive and largely performative justification for the use of force. The threshold for self-defence has significantly thinned, with invocations of Article 51 functioning less as legal justification and more as ritualised assertion. As Antony Anghie observed, this trajectory risks entrenching a ‘Hobbesian universe’ no longer defined by collective security but by the unilateral prerogatives of powerful states.

What this shift reveals is not simply doctrinal expansion, but a weakening of the authority of states to render violence intelligible as lawful in any persuasive sense. The international legal order thus reveals not only its fragility but its complicity in perpetuating the violence it was established to prevent. While it remains tempting to draw upon ICJ jurisprudence to argue that, despite prevailing exceptions, Article 2(4) of the UN Charter continues to govern, this fails to recognise the deeper crisis this violence now signals. At the same time, presaging an end to world order and the ‘death’ of international law offers little to those living through its effects, for whom violence is not an abstraction but a daily condition.

On violence and the erosion of authority

As Hannah Arendt warned in On Violence, states reach for violence when the normative structures that sustain their authority no longer command belief. Violence in her account, is never foundational: it signals the failure of power, not its expression. The current expansion of self-defence is not a sign of strong states exercising unrestrained authority in the international order, but their inability to sustain it. If states can no longer convincingly distinguish self-defence from aggression, the doctrine no longer stabilises the meaning of lawful force. The question is no longer how violence is being justified, but who retains the authority to render it intelligible as law. Seen in this light, disorder is not simply chaos but a diagnostic condition. It reveals the breakdown in the relationship between law and authority.

The erosion of self-defence hence marks not only a doctrinal shift, but an impasse in the production of legal meaning itself. Where once, legal categories functioned to delimit and constrain violence, they can now be utilised as a vehicle to authorise it. The result is not the disappearance of international law but its transformation into a contested terrain in which its authority can no longer be taken for granted.

Whose violence is legible?

Some will say that contestation was always present. Yet if the authority of states to define lawful violence is eroding, the question becomes from where legal meaning might now emerge. Here, Frantz Fanon in The Wretched of the Earth offers an important vantage point. Unlike Arendt, for Fanon, violence becomes the means through which those excluded from the legal order render themselves visible to expose its hypocrisy and contest its claims of universality.

Fanon is not offering a defence of violence in the same register as state claims to self-defence. Rather, he diagnoses the conditions under which violence becomes the language of those denied recognition from that order. While Arendt’s account reveals the erosion of authority from within, Fanon shows how those excluded from that order force recognition from without. The two accounts are not oppositional: they can be read as complimentary. Where Arendt diagnoses the collapse of authoritative meaning, Fanon shows how new forms of meaning emerge in response.

This use of force does not sit neatly within the traditional confines of international law. Because opinio juris remains state-centric and self-referential, there is little space within existing doctrine to recognise how non-state actors generate normative claims. Although international law affirms that all peoples have the right to self-determination, it has rarely credited the practices through which that right is enacted. As Jan Klabbers has argued, the right itself evidences the right to be taken seriously, yet it has often been reduced to procedural form, rather than legitimating substantive claims to community or to exercise authority.

 Articulating authority: Palestine and normativity from below

These dynamics are already visible in contemporary struggles over Palestine, in the context of an unfolding genocide within the meaning of Article II of the Genocide Convention, where global protest movements are not merely responding to violence but articulating competing claims about legality, authority and self-determination. Now documented as the most geographically widespread social movement of recent times, and arguably modern history, these mobilisations raise a fundamental question: what would it mean to understand such practices as the exercise of the right to self-determination?

What if the combined force of these movements was not treated as external to international law, but as sites in which its meaning is contested and re-articulated? What if the formation of customary international law norms depended not only on state practice, but the expressed commitments of people across communities—if norm formation required actual agreement to patterns of conduct? And if those patterns were documented in real time through a variety of triangulated sources, rather than pronouncements from international institutions and the International Court of Justice? What if legality were anchored in lived experience, rather than state performance?

Disordering international law

To take this seriously requires rethinking international law itself. Disordering international law does not mean abandoning it but reasserting its emancipatory potential. It requires drawing upon the normative ordering of those whose lived experiences are rendered invisible by it. Drawing on Justice Trindade’s reading in the Marshall Islands opinion, scholars and practitioners would be called to think beyond sovereignty understood as ‘rules plus coercion’ and instead think with diverse communities, grounding norms in plural forms of authority and collective meaning-making.

In this sense, like Monica Hakimi, I agree we must reject a sovereigntist view of international law that equates the exercise of authority with the dynamics of state control. As Hakimi describes it, international law is a bramble bush: not a hegemonic force to be taken as given, but the language embodying the struggle between inter-sovereign communities seeking to prevent harm and secure justice.

Conclusion

Seen from this perspective, disorder is not a breakdown but an opening: a space within which competing normative communities contest what counts as violence, self-defence, or justice. The expansion of self-defence signals not merely a doctrinal drift but a deeper crisis in authority—one that exposes the limits of state-centred accounts of legality.

This does not mean that all violence becomes legitimate. Rather, it means that international law can no longer sustain a singular account of what violence is, or who has the authority to decide. Those who govern the existing order resort to violence as their authority erodes; those excluded from it deploy violence to be heard at all. The difficulty is not solely that violence proliferates, but that legal categories through which it is recognised remain unevenly distributed. If international law is to survive this moment, it must listen to those who have always lived in its zones of sanctioned violence. From this perspetive, the future of international law depends not only on restraining violence, but on rethinking the terms through which that violence itself becomes intelligible as law.