The river in between

Earlier still, in April 2025, placed the treaty in abeyance on April 23, the day after the Pahalgam attack killed 26 civilians. The Cabinet Committee on Security (CCS) decision stated that the treaty would be held in abeyance “until Pakistan credibly and irrevocably abjures its support for cross-border terrorism”.

Pakistan’s objections are also about two Indian hydropower projects on the western rivers: the 330-megawatt (MW) Kishenganga project in Jammu and Kashmir and the 850 MW Ratle project on the Chenab River. The controversy is technical in nature that concerns much water each can store in its reservoirs or “pondage”.

The treaty permits India to construct run-of-the-river projects on the western rivers. Pakistan claims the ratle design involves a storage component which is outside the purview of the treaty, and therefore India should not be allowed any such construction on the western rivers.

The treaty provides two mechanisms for resolving differences and disputes. Under Annexure F, certain technical questions can be referred to a neutral expert, while disputes can proceed to a CoA under Annexure G. In 2022, the World Bank appointed both a neutral expert and the chairman of a CoA. It had at the time said that running the two processes concurrently posed “practical and legal challenges”.

India argues that the court can’t run both tracks on the same issue at once and has, therefore, termed the court’s ruling illegal.

“I think it’s very interesting that legal measures are being sought,” Naho Mirumachi, professor of environmental politics at King’s College London, said.

“I think having a court of arbitration always means that these discussions take longer to deal with. It’s not easy to make legal decisions quickly. So I think it’s also a strategic move by India to repeat what they have said in the past and not move from their original position of negotiation,” she added.

India does not recognise the CoA’s August ruling. Even so, experts say the award carries diplomatic weight, if not legal force. “I think diplomatically it carries weight in the sense that countries are now not just engaging in diplomacy between the river-facing countries but also relying on third-party actors, as in this case the CoA. There are also potential ways that countries that are engaged in a deadlock could look to other third-party actors, such as mediators.”

“What I think Pakistan is doing is looking at multiple ways of trying to break this deadlock, this very ambiguous situation, and trying to see what kind of tools and means they have to move this negotiation along,” she added.

Pakistan’s pursuit of international forums has helped it gain sympathy whether or not it produces a binding outcome. “From sympathy comes aid and assistance. From that sympathy come big players like the United States and European countries sympathising with Pakistan. And that has a great advantage in the political arena,” Uttam Kumar Sinha, senior fellow at the Manohar Parrikar Institute for Defence Studies and Analyses, said.

“The whole idea of the treaty was peaceful coexistence that hasn’t existed because of Pakistan’s continuous cross-border terror activities, so you have actually breached the very preamble on which this treaty was formed. That has been demolished,” he added.

Linking water disputes for leverage is not unique to India. Türkiye did much the same to Syria in the 1990s, after completing the Atatürk Dam on the Euphrates, it threatened to cut the river’s flow unless Syria stopped harbouring the Kurdistan Workers’ Party and its leader, Abdullah Öcalan.

Syria held out for several years. But pressure escalated in 1998 when Turkiye massed troops on the border. Syria expelled Öcalan and signed the Adana Agreement. Water cooperation between the two countries eventually resumed.

“I think water has always been wrapped up in other issues, whether they be military issues or trade issues or immigration issues, etc. And so this is a strategy that countries have used, not just in the case of India or Pakistan, other countries have done this as well,” Mirumachi said.

“Trying to solve very big issues of militarisation, of regional conflict, might not be done simply by figuring out how to use the river,” she added.

The IWT has weathered three wars and years of political tension between India and Pakistan. But its longevity does not mean it fits current environmental realities. The Indus basin is warming, and its hydrology is changing. Political debate about the treaty, however, remains centred on sovereignty, security and law. Climate change takes a back seat.

Within weeks of the abeyance, India halted meetings of the Permanent Indus Commission and stopped the routine exchange of hydrological data that the treaty had provided for 65 years.

“I think sharing data has always been a cornerstone of water diplomacy and cooperation over shared river basins and shared rivers. So I think this continues to be very important when we need to know when these extreme events such as flooding, flash floods, or droughts occur,” Mirumachi said.

“Without good coordination of data, this might put already precarious livelihoods further at risk,” she added. 

On August 26, the collapse of the Langtang Lirung glacier in Nepal triggered catastrophic flooding through the Bhotekoshi and Trishuli river systems. Nepal’s death toll stood over 1,400, with more than 5,700 people still missing, according to the country’s National Disaster Risk Reduction and Management Authority. Like the Trishuli, the Indus originates in a Himalayan environment exposed to glacial and seismic hazards.

“I think, using the base of a legal structure like a treaty, countries are going to have to make more effort to see how the existing legal framework can be adapted, can be adjusted for a new reality of these hydroclimatic extremes, of extreme weather hazards, as we’ve seen in places like Nepal,” Mirumachi said.

However, climate instability is not the only source of stress on the treaty. According to experts, Pakistan’s problem is not the depletion of its water supply but the way it is currently being managed. Agriculture accounts for almost 90 per cent of the water consumption, and farmers rely heavily on old flood-irrigation methods that waste large amounts of water. Pakistan stores less than 10 per cent of the water it receives from seasonal rains and melting snow.

“Pakistan has the larger share of the watershed, and the basin lies more in Pakistan. So they have enough water, really. The problem in Pakistan really is their own water management, which is rated as one of the worst in the world,” Sinha said.

India’s hydropower development in Jammu and Kashmir has continued through this period. The Union Territory’s installed capacity is projected to rise from 3,540 MW to above 5,164 MW by December 2026, a 46 per cent increase, as the Pakal Dul and Kiru hydropower plants on the Chenab River are near completion. The 120-year-old Mohra power plant on the Jhelum is also being revived.

Pakistan’s diplomacy at the UN has thus far not produced any collective action against India. No UN General Assembly resolution has been passed, and nothing has moved India’s position. Pakistan maintains that the water dispute should be separated from the question of terrorism. The two agrarian economies which depend on the same river are now watching it from opposite sides.