Rivers in Peril: The Collapse of the Indus Water Treaty and the Future of South Asia’s Water Security

“‘The cancellation or what you call the abeyance of the Indus Water treaty is not anything which is practical but it is very political; it is politically dividing these two countries and creating huge mistrust. Just in May, these two countries were on the verge of nuclear war so anything can happen”.

Ashok Swain, Episode 268 of the International Risk Podcast

On 23 April 2025, a day after the Pahalgam attack in the India-administered Jammu and Kashmir that killed 26 civilians, Indian Foreign Secretary Shri Vikram Misr announced that the Indus Water Treaty of 1960 would be “held in abeyance with immediate effect, until Pakistan credibly and irrevocably abjures its support for cross-border terrorism”, a charge that Islamabad denies.

The suspension came amid the worst India-Pakistan hostilities in decades. On May 7th, India launched punitive missile and air strikes across Pakistan and Pakistan-administered Kashmir, prompting retaliatory strikes from Pakistan, most of which were intercepted by India’s air and missile defence systems. Islamabad also threatened to abrogate the Simla agreement, a cornerstone of post-1971 relations between the two states. Although a ceasefire was declared on May 10th, the Indus Water Treaty remains suspended, with India resolute that this move is permanent.

Having previously withstood three wars between India and Pakistan—1965, 1971 and 1999— along with diplomatic breakdowns and even nuclear tests, this marks the first time tensions have disrupted the Treaty itself. The suspension risks destablising the future of water security and peace in the Indus basin, with Pakistan’s Defence Minister Khawaja Asif explicitly warning that any attempt to block or disrupt the Indus River flows allocated to Pakistan will be treated as an “act of war“.

Background on the Indus Water Treaty

The Indus River Basin is one of the world’s largest river systems, primarily traversing Pakistan and India but also extending into China and Afghanistan, and supports over 200 million people who depend on its waters for their livelihoods. Water-sharing cannot be separated from the Kashmir dispute—India claims all of Kashmir, Pakistan claims all but the areas controlled by its ally, China—and this controversy dates back to the partition of British India in 1947. Both countries realise that control of Kashmir comes with control of the river systems that sustain both heavily agricultural economies.

After years of negotiation, with mediating help from the World Bank, the Indus Water Treaty was signed in 1960. Its terms gave Pakistan exclusive control over the three “Western rivers” (Indus, Jhelum, Chenab), though they all flow first through India, and India exclusive control over the three “Eastern rivers” (Ravi, Beas, Sutlej). India was permitted limited use of the Western Rivers for domestic needs, non-consumptive uses, restricted irrigation and run-of-the-river hydropower, under strictly regulated conditions to ensure downstream flow. The treaty also established the Permanent Indus Commission (PIC) and mandated data sharing.

The treaty has been praised for being one of the few bilateral accords that was honoured peacefully between the two nuclear-armed adversaries for over six decades. It facilitated water and irrigation management to continue even in the backdrop of war and military skirmishes. For years, the World Bank showcased it as a rare success in international water diplomacy. Yet today, in the current environment, that legacy is unravelling.

Significance of the Suspension

Immediate Consequences

Since the suspension, India has ceased sharing hydrological data, withheld flood warnings and stopped attending PIC meetings. In early May, India curbed the Chenab River flows via the Baglihar dam by nearly 90% and carried out reservoir sediment flushing at the Salal and Baglihar dams, blocking sections of the river with silt deposits. Pakistan received no prior notice. These actions mark India’s first tangible operations outside the treaty’s terms.

During a public address at the beginning of May, Prime Minister Narendra Modi declared, “Now, India’s water will flow for India’s benefit, it will be conserved for India’s benefit, and it will be used for India’s progress”. In practice, however, the impact remains limited for now because India lacks the large-scale storage, diversion canals and dam capacity to substantially block or divert Pakistan’s share. In conversation with Dominic Bowen on the International Risk Podcast, Ashok Swain noted that another barrier India faces is that “the geography doesn’t allow India to divert the water to its mainland”, referencing the Himalayan mountains.

Even so, manipulating existing infrastructure can cause disruption as was witnessed by the incidents on the Chenab River and this will only become more notable in the dry season when flows are low, storage is critical and timing matters. The risks will be compounded if India continues to withhold flood data. Moreover, if India accelerate new hydropower projects—especially as in the absence of the treaty framework, India has no obligation to secure the prior consent of Pakistan—the long-term threat to Pakistan’s water supply and, in turn, its agriculture, could be severe.

Trust Deficits

The suspension has eroded any sense of bilateral trust between India and Pakistan, signalling a dangerous willingness to discard binding international commitments for short-term political gain. The move sets a precedent that could ripple across other fragile transboundary basins such as the Nile or Mekong, where power asymmetries and geopolitical tensions already strain cooperation. India’s suspension underscored how easy it is for a water-sharing arrangement to be dismantled; the risk is that this could set a precedent, echoing a Thucydides logic where the strong take what they can and the weak scramble for what they can get.

As Ashok Swain pointed out on the podcast, “‘The cancellation or what you call the abeyance of the Indus Water treaty is not anything which is practical but it is very political; it is politically dividing these two countries and creating huge mistrust. Just in May, these two countries were on the verge of nuclear war so anything can happen”.

India’s other neighbours are also watching closely. With the Ganges Treaty up for negotiation in 2026 with Bangladesh, New Delhi’s unilateralism risks burdening future talks and undermining its credibility as a regional partner.

Risk of Escalating Conflict

The suspension marks a destabilising shift for one of South Asia’s most enduring cooperative mechanisms between two rival nuclear states. To Pakistan’s Defence Minister’s warning that any attempt to block or divert Pakistan’s water would be treated as an “act of war”, he added that Islamabad would respond with “full force across the complete spectrum of National Power”, a pointed reference that Pakistan will not exclude the option of nuclear weapons. The risk of rapid escalation should not be dismissed as inconceivable. Swain cautioned on the podcast that if leaders “jump into any sort of war, that war, unless it stops, it can also take the nuclear side”.

Likewise, Filippo Menga, a leading scholar of water politics, writes that the suspension was a “grim milestone in the collapse of the global order” and warns that risks of escalation could be “catastrophic not just for South Asia but for the world. If resource nationalism becomes the norm, no river basin and no international agreement will be safe”. He argues that the move not only reflects the erosion of international law, the rise of unilateralism but the risk of transforming the Indus from a symbol of peace that has sustained civilisations for milennia into an instrument of coercion and conflict.

Water as a Weapon

Water weaponisation is defined as the deliberate use of water to harm or gain leverage over an adversary. Its potency lies in exploiting the fundamental human need for water for survival by deliberately rendering it scarce or insecure. The risks have been amplified by climate change as it is intensifying water stress and vulnerability; in this way, creating ripe conditions for manipulation. Both state and non-state actors have recognised how control over water can be used as a weapon of war. Marcus King, a leading scholar on the subject, has explored these dynamics in Weaponising Water: Water Stress and Islamic Extreme Violence in Africa and the Middle East, showing how groups like ISIS and Boko Haram in Nigeria have exploited water resources and human reliance on it to advance political and military objectives.

The suspension of the Indus Water Treaty fuels fears of water weaponisation between India and Pakistan. Potential tactics could include creating “water bombs” by suddenly releasing held water or flushing silt downstream to damage infrastructure and farmland intentionally. Withholding flood would also undermine Pakistan’s ability to prepare for disasters, especially in a country already prone to extremes, as seen last month when a sudden downpour of 150mm (6 inches) within an hour caused over 360 deaths in northern Pakistan.

Ashok Swain also warned of the catastrophic knock-on effects if dams became military targets: “If Pakistan and India go to war over water, if they start really attacking each other’s dams, forget about nuclear war. If they attack each other’s dams in Punjab and Kashmir, the whole subcontinent will be going through a food insecurity crisis for at least 10 to 15 years”.

Pandora’s Box: China

The decision to suspend the Treaty could end up backfiring, Swain argues, opening a Pandora’s box for China. As the upstream power on the Yarlung Tsangpo (Brahmaputra), Beijing could adopt the same rationale as India to restrict flows to northeast India if relations deteriorate, legitimising the very weaponisation India has long opposed.

China has already begun construction of the world’s largest dam system on the Yarlung Tsangpo in Tibet, just 30km from the Indian border, raising alarm in New Delhi, especially as China has signed no transboundary water-sharing treaties and asserts full sovereignty rights over water for upstream states. If India normalises unilateralism on the Indus, it risks encouraging Beijing to justify restrictions or diversions on either the Brahmaputra and the Indus upstream of India—where China has so far refrained from large-scale development—with potentially dire consequences for India.

The danger for India is compounded by China’s close alignment with Pakistan, a relationship Swain said is described as being between “Iron Brothers” with China pledging to stand by it. Already in the conflict in May, Pakistan used Chinese fighter jets and missiles against India. If New Delhi were to weaponise water against Islamabad, Beijing could come to Pakistan’s side and retaliate in kind, using its upstream leverage against India.

Silver Lining: Opportunities for Reform?

Even though the Indus Water Treaty has long been praised as a successful cooperative mechanism, it had its weaknesses. Ashok Swain on the podcast stated that “I don’t call it [Indus Water Treaty] a water treaty. I call it a partition. A water partition”. By dividing rather than sharing, the treaty failed to incentivise cooperation, something urgently needed as climate change intensifies stress in what is already the world’s second most water-stressed basin.

The treaty also excludes other riparians, China and Afghanistan, inhibiting the possibility of basin-wide management. Furthermore, the 1960 architects could not have foreseen the full extent of 21st century challenges such as climate change, rapid population growth and hydropower demand, leaving it ill-equipped for today’s realities.

“I don’t call it a water treaty. I call it a partition. A water partition.”

Ashok Swain Describing the Indus Water TreaTY

It is also true that the suspension did not come as a complete surprise. As Swain mentioned on the podcast, Narendra Modi had been claiming that he would suspend the treaty since 2016, when he famously exclaimed after the Uri attacks that “blood and water cannot flow together”. In recent years, disputes over the Kishenganga and Ratle hydroelectirc projects have escalated tensions, with Pakistan arguing they violated the treaty and India insisting they complied. With the Treaty giving Pakistan control of roughly 80% of the Indus flows and India only 20%, Modi’s government has repeatedly pushed for renegotiation, arguing that it disproportionately favours Pakistan. In 2024, India even called off all PIC meetings, demanding discussions on revisions.

The suspension could thus be an inflection point to revisit these limitations and revive basin-wide initiatives. First, though, bilateral trust must be rebuilt; without it, there is little chance of India and Pakistan returning to the negotiating table. For now, the suspension is largely symbolic, but its political weight is enormous and the risks of long-term disruption loom.

Listen here to hear Dominic Bowen in conversation with Professor Ashok Swain on the International Risk Podcast as they unpack the major implications of India’s decision to suspend the Indus Water Treaty.