Indus Waters Treaty Explained: What Happens If India Suspends the Treaty With Pakistan?

In the wake of the deadly Pahalgam terror attack, which claimed the lives of 26 Indian tourists, India has formally ordered the temporary suspension of the Indus Waters Treaty (IWT) with Pakistan. Announced on Wednesday and officially communicated to Pakistan the following day, the decision cites 'sustained cross-border terrorism' as the principal reason behind the move. This has sparked a critical question: Can India actually suspend the treaty and block the flow of water to Pakistan? Let’s examine the legal, infrastructural, and environmental challenges such a move would involve.
A Watershed Moment in India-Pakistan Relations

The Indus Waters Treaty, brokered by the World Bank and signed in 1960 by Indian Prime Minister Jawaharlal Nehru, Pakistani President Ayub Khan, and Sir William Iliff of the World Bank, has long been viewed as a rare example of enduring cooperation between the two countries despite their ongoing tensions and disputes over the years. After the Partition of British India in 1947, control over the rivers flowing into Pakistan rested with India, leading to significant tensions. By 1954, the World Bank intervened to mediate the dispute, and after years of negotiations, the treaty was signed on September 19, 1960.
The treaty aimed to address the water-sharing disputes that had emerged post-Partition, ensuring the continued flow of water for both countries. It has been considered a significant diplomatic achievement, as it provided a framework for cooperation even during periods of political tension.

Under the treaty, India received control over the three eastern rivers—Ravi, Beas, and Sutlej—while Pakistan was granted rights over the three western rivers—Indus, Chenab, and Jhelum. While India was permitted limited non-consumptive use of the western rivers (for purposes such as irrigation, hydropower, and navigation), it refrained from fully exploiting even those rights, partly due to political sensitivities and technical constraints.
India has so far used only about 10% of the water it is entitled to under the IWT, although the treaty allows for up to 20%. Pakistan, meanwhile, depends on the Indus river system for around 80% of its agricultural irrigation, making the treaty vital to its food and water security. The World Bank's then-Vice President William Iliff had famously warned in 1961 that without the Indus waters, Pakistan would become a desert.
The current crisis has drawn renewed scrutiny on this dependency. India’s move to place the treaty in abeyance, while not an outright withdrawal, introduces significant uncertainty for Pakistan, which is already grappling with economic instability, soaring inflation, and food insecurity. Pakistani Prime Minister Shehbaz Sharif’s office has denounced India’s decision, warning that any attempt to divert or block river flows would be tantamount to “an act of war.”
Can the Waters Be Diverted? Legal, Infrastructural, and Environmental Constraints

India’s decision to place the Indus Waters Treaty (IWT) in abeyance raises the question: is it even possible to divert or block the flow of the western rivers—Indus, Jhelum, and Chenab—into Pakistan?

Legally, the treaty does not include a formal exit clause. Article IX, which deals with disputes, offers no provision for unilateral withdrawal. India’s suspension thus falls into a legal grey zone, potentially inviting international arbitration.
Any move to significantly alter the flow of the rivers would require substantial new infrastructure. Currently, India lacks the dams and reservoirs necessary to control the western rivers’ flow at scale. Projects like the 850 MW Ratle, 1,000 MW Pakal Dul, 624 MW Kiru, and 540 MW Kwar hydroelectric plants on the Chenab River are underway but far from operational capacity. Even if completed, these projects are designed primarily for hydropower generation rather than large-scale water diversion. Experts estimate that building the necessary infrastructure to meaningfully restrict water supply to Pakistan would take years and involve extensive financial, environmental, and diplomatic costs.
Geologically, the task is even more daunting. The Kashmir Valley, through which much of the water flows, is surrounded by the towering Pir Panjal and Himalayan ranges. The valley lies at an average altitude of 1,850 meters, while the surrounding mountains reach 5,000 meters—forming a natural barrier that makes diversion physically implausible. The valley lacks natural basins or depressions to store excess water, and any attempt to construct large reservoirs would require unprecedented excavation and infrastructure in a seismically active and ecologically fragile zone.
Environmentally, rerouting or halting river flows would carry enormous risks. These rivers are integral to the ecological stability of Kashmir and downstream regions. Disruptions could trigger landslides, affect biodiversity, damage aquatic habitats, and spark water crises on both sides of the border. Any large-scale construction would also involve deforestation and displacement, likely sparking significant local and international opposition.

Nonetheless, the government appears determined to press forward. Officials argue that India must now leverage every legal and strategic tool available to respond to terrorism. The treaty, they claim, was conceived in a different era—one that did not anticipate the persistence of state-supported non-state actors waging asymmetric warfare across borders.
Strategic Fallout and Regional Ramifications

India's suspension of the Indus Waters Treaty (IWT) is not an isolated gesture but part of a broader recalibration of its approach to Pakistan. Alongside the treaty’s abeyance, India has revoked SAARC visa exemptions for Pakistani nationals. The India-Pakistan border at Suchetgarh in Jammu has been closed to civilians. The Border Security Force (BSF) has halted civilian movement at the Octroi Post in Suchetgarh and shut the Attari-Wagah border in what has been described as a move on a “wartime footing.” These steps underscore a strategic shift toward using non-military, yet high-impact, instruments of statecraft in response to national security threats.
Pakistan, in turn, has threatened a series of retaliatory actions. These include scrapping the Shimla Agreement, suspending overflight rights for Indian aircraft, banning Indian airlines, shutting down visa services for Indian citizens, and closing the Wagah border. While some of these responses are largely symbolic, others—particularly airspace closure—could inflict tangible economic costs on India's civil aviation and trade logistics.

Regionally, the move has raised alarms. The Indus Waters Treaty has long been hailed as a rare example of successful transboundary river cooperation, even between hostile neighbors. Its erosion could set a troubling precedent in South Asia, where water-sharing disputes already complicate India’s relations with Nepal, Bangladesh, and China. Moreover, China’s vested interests in Pakistan-administered Kashmir—particularly in infrastructure projects under the China-Pakistan Economic Corridor (CPEC)—add another layer of geopolitical uncertainty. A disruption to the Indus basin's governance framework could pose risks to these ventures, many of which are situated close to key river systems.