At the heart of international law lies a deceptively simple Latin maxim: pacta sunt servanda – agreements must be kept.
This principle is often described as ancient, but such a description understates its significance. It is not merely a historical inheritance from Roman law or a technical legal doctrine codified in Article 26 of the Vienna Convention on the Law of Treaties. Rather, pacta sunt servanda is a natural principle of ordered coexistence among sovereign entities and the absolute bedrock upon which the modern international system rests. Without a shared expectation that commitments freely undertaken will be honoured in good faith, diplomacy degenerates into tactical opportunism, and law collapses into power.
The international system, unlike domestic legal orders, lacks a central sovereign authority capable of enforcing compliance through coercion. Its stability therefore depends disproportionately on voluntary restraint, predictability, and trust. Treaties provide this structure. They are not just legal instruments but the binding glue of international relations, translating political understandings into durable obligations. When states negotiate, sign and ratify treaties, they signal an intention to substitute raw power with rules, and unilateral discretion with mutual restraint. This is why the erosion of treaty compliance is not a technical legal issue; it is a systemic risk to global order.
The Treaty System performs multiple interlocking functions. At the most basic level, it creates binding obligations that stabilise expectations. States plan economic investments, security arrangements, environmental management and technological cooperation on the assumption that treaty commitments will not be casually reversed. Beyond this, treaties institutionalise cooperation by embedding procedures, review mechanisms and dispute resolution frameworks that allow disagreements to be addressed before they metastasise into crises. In this sense, treaties function as early-warning systems. They provide channels for dialogue, clarification, and adjudication precisely when political tensions begin to rise.
Yet today, the international system is witnessing a disturbing trend: the unilateral abandonment, selective interpretation, or quiet hollowing-out of treaty obligations. This is occurring across domains; arms control, trade, environmental governance, investment protection, human rights and transboundary resource management. What makes this trend particularly alarming is not only its frequency but its normalisation. Treaty withdrawal, suspension, or non-implementation is increasingly justified in the language of domestic politics, national sovereignty, or strategic necessity, often without serious engagement with the systemic consequences.
Recent decades offer a sobering catalogue. Arms control agreements painstakingly negotiated over years have been allowed to lapse or been withdrawn from, undermining strategic stability and reviving arms race dynamics. Trade agreements have been overridden through unilateral tariffs and countermeasures that bypass agreed dispute settlement mechanisms. Environmental commitments have been diluted or delayed despite escalating climate risks. In each case, the immediate justification may differ, but the cumulative effect is the same: a weakening of the shared belief that international commitments constrain behaviour.
This erosion has profound implications for international relations order. When treaties are disregarded by powerful states, the damage is not contained to the immediate parties. It sets precedents that others inevitably follow. Smaller and middle powers, observing that rules bind selectively, recalibrate their behaviour accordingly. Compliance becomes conditional, reciprocity weakens and norm-breaking becomes contagious. The result is a gradual shift from a rules-based order to a transactional one, where obligations are honoured only so long as they align with short-term interests.
Nowhere is this more dangerous than in transboundary arrangements governing shared resources. Rivers, aquifers, fisheries, migratory species and shared ecosystems depend on cooperative management across borders. Treaties governing these resources are not optional conveniences; they are essential instruments for preventing conflict. When upstream states ignore water-sharing agreements, or when environmental safeguards are unilaterally relaxed, downstream impacts quickly acquire political and security dimensions. History demonstrates that resource disputes rarely remain technical; they become symbols of sovereignty, survival, and injustice.
Treaty violations in such contexts establish particularly harmful norms. They signal that power asymmetry can override legal obligation, encouraging pre-emptive behaviour by weaker states and securitisation of what should remain cooperative domains. Once trust erodes, even routine data-sharing or joint monitoring becomes suspect. The treaty’s early-warning function fails and disputes that could have been managed through institutional mechanisms begin to escalate outside legal frameworks.
The weakening of treaty-based dispute resolution is especially troubling. Most modern treaties incorporate graduated mechanisms, consultations, joint commissions, mediation, arbitration, or adjudication designed to contain disputes at an early stage. These mechanisms reflect a recognition that disagreement is inevitable, but conflict is not. When states bypass or undermine these processes, they deprive the system of its shock absorbers. Disputes are no longer filtered through law and procedure; they are expressed through unilateral measures, retaliation, or coercive diplomacy.
This trend also corrodes the legitimacy of international institutions. When treaty obligations are treated as optional by some, institutional rulings are dismissed as political by others and compliance becomes uneven, confidence in multilateral governance declines. This feeds domestic scepticism about international law, reinforcing nationalist narratives that portray treaties as constraints imposed by outsiders rather than voluntary commitments entered into by sovereign states. The vicious cycle between domestic politics and international norm erosion accelerates.
In this context, the role of the UNSC assumes renewed importance. While not all treaty violations fall within its mandate, the council bears primary responsibility for the maintenance of international peace and security. Fraying respect for treaties should therefore be understood as an early indicator of systemic stress. Many conflicts that later demand UNSC intervention begin as unresolved treaty disputes over borders, resources, security arrangements, or political commitments. Treaties are often the first line of defence; when they fail, the costs of intervention rise exponentially.
UNSC members, particularly the permanent members, must take these ominous signals seriously. This requires more than rhetorical support for international law. It demands consistency between declared commitments and actual behaviour. When permanent members themselves disregard treaties or selectively invoke international law, the normative damage is magnified. Credibility is indivisible; it cannot be compartmentalised.
Upholding pacta sunt servanda is therefore not an altruistic gesture but a core strategic interest in preserving a stable and predictable international environment. Proactive engagement is essential. Emerging disputes within treaty frameworks should be addressed early, through diplomatic facilitation, technical assistance, and political pressure where appropriate. The goal should not be punitive enforcement but restoration of compliance and confidence.
Preventive diplomacy, grounded in treaty obligations, remains far less costly than crisis management after escalation. Re-investing in dispute resolution mechanisms, strengthening compliance review processes, and resisting the politicisation of legal obligations are practical steps that can reinforce the system.
Ultimately, the principle of pacta sunt servanda is not about legal formalism but about trust. International relations cannot function on power alone. Even the most powerful states depend on predictable rules to manage complexity, reduce uncertainty, and coordinate action on global challenges that no state can address alone. Climate change, pandemics, technological governance, and financial stability all require durable commitments sustained over time and across political cycles.
The flashing red lights now visible across the treaty landscape should therefore be read as warnings, not inconveniences. If the binding glue of the international system continues to weaken, the unraveling will not be selective. It will affect security, development, and cooperation alike.
Reaffirming pacta sunt servanda in practice, not just in principle, is essential to arrest this decline. The alternative is a world where agreements are temporary, law is instrumental and conflict becomes harder to prevent and costlier to resolve.
The writer is a trade facilitation expert, working with the federal government of Pakistan.
