The threat of all-out war between India and Pakistan—South Asia’s rival nuclear-armed capitalist powers—continues to rise following New Delhi’s illegal air strikes on the night of May 6-7 against targets in Pakistan and Pakistan-controlled Kashmir.

Exchanges of artillery and mortar fire across the countries’ disputed border have erupted every night since. Both of the reactionary communalist regimes have accused the other of launching major attacks across the Line of Control that separates Indian- and Pakistan-held Kashmir and, respectively, in India and Pakistan proper.

Although little commented on in the western media, a key factor in the escalation of tensions is the Indian government’s provocative decision to suspend its participation in the Indus Waters Treaty (IWT).

New Delhi announced the suspension on April 23, less than 24 hours after a terrorist attack in Indian-administered Kashmir for which it immediately declared Islamabad responsible.  

By threatening a resource vital to Pakistan’s economy, New Delhi effectively closed off avenues for de-escalation in a region already reeling from decades of imperialist intervention and the whipping up of communalism by New Delhi and Islamabad.

Predictably, Pakistani political leaders responded with bellicose threats of their own. Pakistan Prime Minister Shehbaz Sharif called the treaty’s suspension a “declaration of war,” while Bilawal Bhutto-Zardari, the Chairman of the Pakistan People’s Party (PPP) told an April 25 rally, “The Indus is ours and will remain ours—either our water will flow through it, or their blood.”

If not rapidly rescinded, the suspension of the treaty risks to have catastrophic consequences for the economy and the people of Pakistan, with the brunt of any disruption or interruption of the Indus’ water flow falling on the country’s tens of millions of impoverished workers and toilers. The vast majority of Pakistan’s agriculture and a significant portion of the country’s electricity generation depend upon water from the Indus.

“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,” Indian Prime Minister Narendra Modi said on Tuesday, as Indian fighter jets were preparing to mount cross-border attacks deep inside Pakistan under the cover of darkness. Modi did not name Pakistan when he proclaimed that “India’s water” “will no longer flow outside,” but his target was obvious.

India’s suspension of the IWT, which came into force in 1960, is unprecedented. Despite having fought two declared wars, several undeclared wars, and countless border skirmishes with Pakistan over the past 65 years, never before has New Delhi suspended the treaty.

For now, Islamabad is reportedly preparing to challenge the IWT’s suspension at the Permanent Court of Arbitration or at the International Court of Justice in The Hague, on the basis that New Delhi has violated the 1969 Vienna Convention on the Law of Treaties. It is also considering raising the issue before the United Nations Security Council.

India’s move was far from an impulsive retaliation. New Delhi has threatened to withdraw from the treaty since at least 2016.

India’s weaponization of water scarcity in Pakistan is part of a concerted attempt by India’s Narendra Modi-led Hindu supremacist government to “change the rules” in New Delhi’s relationship with Islamabad—and all with the aim of establishing India as the regional hegemon.

In doing so, the Indian bourgeoisie seeks to assert its “right” to flout established norms of bilateral treaties and international law. Such an aggressive course of action, however, is hardly conceivable outside of its “global strategic partnership” with the United States. The US has neither condemned India’s air strikes on targets in Pakistan or Pakistan-controlled Kashmir, nor criticised New Delhi’s decision to abandon the IWT.

Washington previously emboldened New Delhi by supporting its cross-border “surgical strikes” on Pakistan in 2016 and 2019. After Indian air strikes went ahead on Tuesday after prolonged speculation that an attack was imminent, Trump and top officials in his administration issued only the most general remarks expressing their hope that the conflict would be “resolved.”

For more than two decades under Democratic and Republican administrations alike, Washington has sought to build up India as a counterweight to China, while ensuring, in partnership with New Delhi, US dominance over the Indian Ocean—whose sea lanes are critical to China’s access to resources and trade with the world.

As part of its drive to harness India to its military-strategic offensive against China, US imperialism has dramatically downgraded its strategic ties with Pakistan, its former Cold War ally, shifting the balance of power in the region in India’s favour. In response, Pakistan has doubled down on its “all-weather” strategic partnership with China, further antagonizing Washington and New Delhi.

An opinion column in the widely read Pakistani English-language daily Dawn captured the bleak geopolitical prospects for Islamabad in a commentary by Khurram Husain: “Pakistan has not succeeded in getting India to reverse its steps of 2019, through which it absorbed the occupied territory of Jammu and Kashmir into its federation. It now faces the uphill challenge of getting India to return to its commitments under the IWT.”

The IWT—brokered by the World Bank after the 1947 communal partition of the subcontinent into an expressly Muslim Pakistan and a predominantly Hindu India had territorially divided the Indus river basin—was designed to avert conflict over its waters. The agreement allocated approximately 80 percent of the Indus system’s water to Pakistan, granting it control over the Chenab and Jhelum tributaries and the main stem of the Indus. India retained rights over the eastern tributaries of the Indus—the Ravi, Beas, and Sutlej rivers.

India was also permitted limited, non-consumptive use of the western rivers, primarily for run-of-the-river hydroelectric projects that did not involve significant storage or diversion. It was obliged, however, to share detailed information on any planned projects on the western rivers, and Pakistan was entitled to raise objections if it believed a project would threaten its water supply.

When India announced it was suspending its participation in the IWT, it was widely assumed that India’s lack of major infrastructure would prevent any immediate disruption to Pakistan’s water supply. However, this assumption has proven at least partially incorrect. According to unnamed Indian officials cited by Reuters, India can now “stop sharing crucial information and data on release of water from barrages/dams or on flooding,” and “will also not be obliged to release minimum amounts of water during the lean season.” Others confirmed that India could divert water “within months” for its own agricultural needs.

On May 5, Reuters reported that India has begun work to increase reservoir holding capacity at two hydroelectric projects among several in Kashmir situated on rivers allocated to Pakistan. This effort began with “reservoir flushing,” a process that releases sediment-laden water downstream, potentially causing sudden inundation, followed by a reduced flow as the reservoirs are refilled. According to Reuters, such operations were previously constrained by the treaty’s requirements.

Reuters further reported on May 6 that the Modi government has “advanced the start date of four under-construction hydropower projects in the Kashmir region by months” after suspending the IWT. All four projects are built on the Chenab, and Reuters noted that the construction of these were generally opposed by Pakistan. As it rapidly advances to disrupt the IWT settlement, New Delhi has made it clear that it is determined to deprive Pakistan of its Indus water lifeline.

The total population living in the Indus basin is estimated at roughly 300 million, the overwhelming majority of whom are in Pakistan. According to some estimates, 90 percent of Pakistan’s population depends on the Indus. Its most populous province, Punjab, lies entirely within the drainage area of the Indus, as does Khyber Pakhtunkhwa, while most of Sindh and eastern Baluchistan also fall within the basin. So vast is the dependence on the Indus that 80 percent of Pakistan’s cultivated land relies on its water, accounting for nearly 25 percent of the country’s GDP.

The strain on the Indus system is further illustrated by the increase in Pakistan’s population—from 34 million in 1951, just a few years prior to the IWT’s signing, to over 240 million today. According to Pakistan’s Population Census Organization, per capita water availability dropped from 5,260 cubic meters in 1951 to 2,129 cubic meters in 1981, 1,611 cubic meters in 1991, and 908 cubic meters in 2016.

In 2020, the United Nations Development Programme projected that some 207 million people in Pakistan will face “absolute scarcity” of water, with less than 500 cubic meters available per person by 2025, effectively turning Pakistan from a “water-stressed” into a “water-scarce” country. The situation is exacerbated by climate change. Accelerated glacial melt in the Himalayas, while causing devastating floods in the near term, will rapidly lead to lower summer water supply to the Indus.

The impact on Pakistan’s population that depends on Indus water does not stop at the estimated 43.5 percent of the labour force that works in agriculture. Water scarcity is a significant contributor to worsening food security in the crisis-ridden country. According to the World Food Program, “82 percent of the population cannot afford a healthy diet.”

The social consequences of an all-out war for India and Pakistan’s 1.7 billion people is a matter of utter indifference to both of the reactionary bourgeois regimes involved, to say nothing of the imperialist powers. According to the UNDP’s latest Global Multi-Dimensional Poverty index, released in October 2024, India and Pakistan are the two countries worldwide with the largest populations (234 million and 93 million respectively) living in acute multidimensional poverty. This means they frequently lack adequate housing, sanitation, nutrition, cooking fuel, electricity, and the opportunity to attend school.

New Delhi’s abrogation of the IWT is a step from which it is hard to back down, all the more so given the reliance of the BJP government on the hawkish, rabidly right-wing Hindutva forces it has rallied around the “strongman” posture of Prime Minister Narendra Modi, especially against Muslim Pakistan. “We will ensure no drop of the Indus River’s water reaches Pakistan,” India’s water resources minister, Chandrakant Raghunath Paatil, gleefully declared on X.

Even if the current clashes stop short of triggering a full-scale war, India’s disruption of Indus water flows to Pakistan is set to exacerbate the long-lasting conflict between the two countries and have a disastrous impact on the lives of hundreds of millions of workers and rural poor. In response to India’s US-bolstered military buildup and its own  growing conventional military vulnerabilities, Pakistan has repeatedly threatened to deploy its nuclear arsenal. Speaking in the hours after India’s initial attack on Pakistan this week, Pakistan Defence Minister Khawaja Asif warned that were India to “impose an all-out war on the region … then at any time a nuclear war can break out.”  

The only way to prevent the outbreak of all-out war and put an end to the horrific social conditions produced by the communal partition of the subcontinent is through the unification of the working class throughout the region, cutting across all the fraudulent divisions deliberately cultivated by the ruling elites. This requires the fight for a socialist and internationalist programme.