A key question is whether Article 62 of VCLT provides sufficient legal basis for India’s action or other legal justifications may be applicable. This inquiry is crucial because invoking the correct principle of international law will enhance the legitimacy of India’s position and highlight Pakistan’s unlawful actions. According to Article 62 of VCLT, unilateral termination of an international treaty is permissible if there is a “fundamental change” in the circumstances that formed the essential basis for consent to be bound by the treaty. Successfully applying this provision requires meeting specific criteria, including “changes of circumstances” that must be “unforeseen” when the treaty was signed and must be “fundamental”. Furthermore, these “fundamental” and “unforeseen” changes should be closely linked to the treaty’s object and purpose.

The International Court of Justice (ICJ) has established that the threshold for invoking Article 62 is exceptionally high. In the 1997 Gabčíkovo-Nagymaros Project case, involving dam construction on the Danube, Hungary argued that political, economic, and environmental developments since the 1977 Agreement constituted a “fundamental change of circumstances”, justifying its termination under Article 62. ICJ rejected this, holding that political and economic shifts were not closely linked to the object and purpose of the treaty, and advancements in environmental knowledge and norms were not entirely unforeseeable.

Given this precedent, it is uncertain whether the security concerns arising from the Pahalgam terror attack would meet the high bar for a “fundamental change of circumstances” as outlined in Article 62. Since India and Pakistan have always had a politically strained relationship, before and after IWT’s negotiation, it could be challenging to contend that the recent terror attack represents a fundamental change in circumstances sufficient for unilateral termination. Additionally, India has cited other reasons for suspending IWT, including changing population dynamics, climate crisis imperatives, and shifts in the water-sharing assumptions when the treaty was signed. Although such changes could potentially qualify as ‘fundamental changes of circumstances,’ they are unrelated to the terror attack. They could have been cited at any time, including before the attack, to suspend the IWT.

If not under Article 62 of VCLT, what other legal justifications can India offer? India could present two alternative justifications. First, international law permits states to take countermeasures in response to another state’s internationally wrongful acts, aimed at compelling the offending state to fulfil its international obligations. Given Pakistan’s support for terrorists who commit attacks like the one in Pahalgam, these acts can be attributed to the Pakistani State. Thus, the terror attacks constitute a violation of Article 2(4) of the UN Charter, which prohibits the use of force against other States, directly or indirectly. By patronising terrorism, Pakistan has also been violating several other international legal norms. Consequently, the suspension of IWT could be justified as a proportionate countermeasure in response to Pakistan’s breach of international law.

Second, India can invoke Article 60 of VCLT, which, along with Article 62, is part of customary international law, to justify the current suspension of IWT. Article 60 provides for the right of reactive termination or suspension of a treaty due to a material breach of treaty provisions by other parties. Since India believes that Pakistan is in breach of IWT, it is well within its rights to suspend IWT until Pakistan adheres to its obligations under the treaty.

In summary, this issue has again underscored that India lacks an effective lawfare strategy to address its adversaries, such as Pakistan. Instead of merely reacting after a major terrorist attack, New Delhi needs to proactively utilise international law as a tool to consistently advance its national interests. This approach requires both a bold vision and enhanced State capabilities.

Prabhash Ranjan is professor, Jindal Global Law School, and Pushkar Anand is assistant professor, Faculty of Law, University of Delhi. The views expressed are personal