Reports of India unilaterally suspending the Indus Waters Treaty have sent ripples through both legal and diplomatic circles. This decades-old water-sharing agreement between India and Pakistan is not just a bilateral accord-it’s a cornerstone of transboundary water governance and a rare example of cooperation between two historic adversaries. The legal implications of its suspension, therefore, deserve serious scrutiny. With few exceptions, treaties are meant to be kept by state parties. Article 26 of the Vienna Convention on the Law of Treaties (VCLT) enshrines the principle of pacta sunt servanda-agreements must be kept. This principle lies at the heart of the international legal system. It ensures that commitments made between states are honored in good faith and not cast aside at the whim of politics or convenience. That said, the VCLT does allow for suspension or termination of treaties-but only under strict and narrowly defined conditions. A material breach, a fundamental and unforeseen change in circumstances, or the literal impossibility of carrying out the treaty-these are the few doors left ajar. But even when these doors are opened, there are formal procedures to follow, and none of them endorse abrupt or unilateral action. Here a questions arises that whether VCLT applicable on Indus Water treaty? This brings us to a key legal wrinkle: the Indus Waters Treaty was signed in 1960, while the Vienna Convention was adopted in 1969 and entered into force in 1980. According to Article 28 of the VCLT, the Convention does not apply retroactively unless the parties agree to it. In this case, India and Pakistan never did. Article 26 of the Vienna Convention on the Law of Treaties (VCLT) enshrines the principle of pacta sunt servanda-agreements must be kept. This means that the Treaty must be interpreted through the lens of customary international law-a body of legal norms built not just on treaties but on the consistent practices and beliefs of states. Unfortunately, this makes the legal terrain murkier, as customary law often leaves greater room for interpretation-and contestation. Crucially, the Indus Waters Treaty itself does not provide any mechanism for unilateral suspension. It includes no withdrawal clause, no sunset provision, and no express provision for a party to opt out. Article XII(3) clearly states that modifications require mutual consent. Simply put, if one party wishes to change the deal, the other must agree. This silence matters. In treaty law, what’s not said is often as important as what is. Without a clause permitting suspension, unilateral action becomes legally dubious at best, and a breach at worst. In the absence of a provision allowing suspension, India’s reported move may be in breach of both the Treaty and broader principles of international law. But what recourse does Pakistan have? The Treaty itself contains a dispute resolution mechanism, but it notably excludes access to the other jurisdictions. Pakistan could, however, seek engagement through diplomatic channels, involve the World Bank as a broker (as it was involved in facilitating the original Treaty), or appeal to international public opinion and the principle of state responsibility-a concept in international law that holds states accountable for breaches of legal obligations. Lastly, even if India justifies its move by invoking broader political or strategic concerns, the legal and geopolitical risks are considerable. Suspending the Treaty doesn’t just affect India and Pakistan-it sets a dangerous precedent for water-sharing agreements worldwide, especially in regions where water is scarce and rivers do not respect national borders. On the other hand, the legal consequences of suspension are clear: the obligations of both parties are put on hold. This mutual effect can have serious implications, particularly in an already volatile region where cooperation over natural resources is often a rare commodity. The writer is a law lecturer at Curtin University and Tweets @AbdullahFazi.