One of international law’s oldest and most hard-won achievements risks being dismantled in plain sight, and the legal community has apparently not yet reckoned with what that would mean in practice for international relations. Article 2(4) of the United Nations (UN) Charter – the prohibition on the use of force – was never just a treaty clause, while also preserving the right of self-defence, which may only be invoked exceptionally. It was the distillation of lessons learned from over seventy million deaths during World War II. The international actors of the post-war order understood, with a clarity born of catastrophe, that a world governed solely by power rather than law was a world perpetually self-destructive for all. That understanding is once again being tested, this time under its severest ordeal, and we are not confident that it is passing the test.

We are not concerned with a single violation – violations have always occurred – but with the way in which they are being framed and absorbed. Powerful states are no longer simply breaking rules and hoping nobody notices. They are increasingly offering legal reinterpretations of those rules, stretching concepts such as self-defence and necessity beyond recognition, with the apparent expectation that the international legal order will simply accommodate their preferred interpretations. This represents a different and more dangerous phenomenon than straightforward non-compliance. If a rule is openly breached, one can at least push back against it. But when a rule is subtly altered, matters become more complicated through a tacit institutionalisation of complicity, as even what can be said is constrained from the outset.

This two-part blog first explores two examples, relevant to the subject matter. The second part analyses these examples in light of the above.

The Gaza Question and the Limits of Legal Tolerance

Gaza has become the most visible stress test of international humanitarian law in a generation. Large-scale military operations conducted under the pretext of self-defence, resulting in significant civilian casualties, have given rise to serious allegations of violations of core principles of international humanitarian law, particularly proportionality and distinction. Indeed, as international law stipulates, proportionality must not be compromised even if the underlying cause is justified, nor may the principle of distinction be disregarded simply because warring parties use civilians as shields.

More concerning is the inability of the international community, including the UN, to respond consistently to these alleged violations, which is generating something more corrosive than impunity – it is generating a settled expectation of impunity. And that expectation, once established, effectively rewrites the content of the law.

Sovereignty as a Compromised Concept

Alongside the erosion of the jus ad bellum, something quieter but equally troubling is happening to sovereignty. Unlawful renditions, military operations on the territory of non-consenting states, and the growing tendency to treat other states’ sovereign decisions as mere inconvenient obstacles reflect a worldview in which sovereignty is a real constraint for weak states but a polite fiction for strong ones.

Double standards are not new – they have always existed – but what is striking now is the brazenness: there is barely any effort left to construct even a minimal legal justification. International lawyers are trained to look for opinio juris – the sense of legal obligation that distinguishes a binding norm from mere habit. When states cease to feel obliged to articulate why their conduct is lawful, we are witnessing the erosion of opinio juris in real time. This is a deeply serious development, as the binding force of customary international law depends upon it.

This is particularly worrisome when dealing with regimes accused of conduct that allegedly endangers international peace and security. In the relatively recent past, based on lessons drawn from post-Cold War military conflicts in places such as the Balkans and Sub-Saharan Africa, the international community developed a set of norms known as the “Responsibility to Protect” (R2P), aligned with the UN’s “Uniting for Peace” principle.

Coined at the 2005 UN World Summit, this principle established a legal framework -approved unanimously by UN members – comprising a three-stage strategy for intervention in states deemed responsible for endangering international peace and security or committing atrocity crimes. Despite institutional constraints arising from the UN Security Council’s voting system, this at least contributed to the development of opinio juris, providing a degree of legal justification and legitimacy for military operations affecting the territorial integrity and sovereignty of states.

Yet, against this background, recent developments in countries such as Venezuela and Iran -and even the aggressive rhetoric concerning the future of Greenland – should be regarded, at the very least, as serious setbacks to the current international legal system. This emerging form of interventionism carries a significant risk of establishing dangerous precedents for similar cases.