The most dangerous river in the world: why the Indus could spark WWIII

Telegraph

25-04-2025

It gave birth to one of Earth's earliest and most mysterious civilisations, halted Alexander the Great, and today sustains some of the planet's most populous cities.
Now the Indus river – the mighty water way that carves its way through what is now Pakistan – could also give us World War III.
On Thursday, India's government announced it was temporarily suspending the treaty that regulates use of the river's waters in response to a terrorist attack that killed 26 tourists in Indian-controlled Kashmir, the worst assault of its kind in the disputed region for many years. Pakistan warned that could be an act of war.
As tensions escalate, the pair have issued tit-for-tat suspensions of visas, with Pakistan halting all trade with India (including via third countries) and expelling a raft of Indian military attaches from the country.
India, whose police have named three of four suspected gunmen behind the attack (two of whom are Pakistani citizens), has meanwhile shut the Attari-Wagah border between the two countries and downgraded diplomatic ties.
Prime Minister Narendra Modi has, ominously, also vowed to pursue those responsible for the attack in Kashmir 'to the ends of the Earth'.
'I say to the whole world: India will identify, track and punish every terrorist and their backer,' Modi said earlier this week.
'For Pakistan it is existential'
As the two nuclear-powered neighbours appear to lurch closer to an all-out conflict than they have in years, the Indus river is more than just a symbol.
'As far as India is concerned, since it is an upstream country, the importance of the treaty is not so great. These agreements are generally more important for downstream countries, like Pakistan. And for Pakistan, it's a life and death issue,' says Himanshu Thakkar, director of the Delhi-based South Asia Network on Dams, Rivers and People.
'For Pakistan it is existential. It is Pakistan's lifeline actually, its agricultural and food lifeline. That's why it is very touchy, and that's why the provisions in the treaty are very stringent. There should be no uncertainty, no loss of predictability. I mean, it is existential dependence. That's why they have called it an act of war,' he adds.
India and Pakistan have battled over water ever since independence in 1947.
The new state of Pakistan was centred on the Indus and would depend on it for water outside the summer monsoon.
But the border created by partition cut right across the waterway and five of its main tributaries. It also split the elaborate canal system the British Raj built to irrigate previously barren portions of western Punjab.
It is one reason the two countries immediately went to war over Kashmir, the mountainous territory through which the Indus flows on its way from China, and where one of its main tributaries rises. It also explains why the conflict has continued to this day, says Dr Chietigj Bajpaee, a senior research fellow for South Asia in the Asia-Pacific Programme at Chatham House.
Securing the headwaters of the Indus became critical. In 1960, after years of tense negotiations brokered by the World Bank, the The Indus Waters Treaty came into force.
The deal handed India full rights to the use of the three western tributaries, but guaranteed Pakistan flow from the Indus itself and its two eastern tributaries – the Jhelum and Chenab – which account for most of its water.
Through a number of wars, one nuclear arms race, and numerous skirmishes, Indian and Pakistani delegations continued to meet every year to review water levels, exchange data on rainfall and river flow, and consult on dispute resolution.
In the small world of water diplomacy, the Indus treaty 'has long been held up as a pillar of stability,' says David Michel, a senior fellow at the centre for strategic and international studies who in 2012 drafted a review of potential water conflicts for the US intelligence community.
'It is more of a divorce settlement than a cooperation agreement, literally dividing the basin in half,' he notes, 'and it is not not flexible or suited to new challenges of climate change – it doesn't address ground water, or water quality, or glacial melt or things like that – but it survived two wars and numerous smaller conflicts.'
Taking it away
India has been allowed to build some dams and take some water from the upstream sections, but only under strict conditions and in coordination with Pakistan. It froze one project in 1987 because of Pakistani objections.
But Modi's government has had the deal in his sights for some time. After a terrorist attack against Indian soldiers in Kashmir in 2016, Modi declared that 'blood and water can't flow together at the same time'. He reiterated the threat after another attack in 2019.
In 2023, New Delhi said it would like to renegotiate the treaty. Then, in August last year, India wrote to Pakistan saying it would suspend the annual meetings of the Indus water commission.
It is testament to the success of the treaty that even this step is incremental: having frozen the treaty, there is no button for prime minister Modi to press that actually would reduce the flow of water to Pakistan. No such infrastructure exists. Building it now could take a decade of construction work.
But there are other ruses. Ignoring the treaty's rules about 'silt flushing' – the practice of clearing out existing Indian dams by opening the sluices – could be used to wreak havoc downstream in the short term, says Tahkkar.
'I hope India doesn't intend to really interfere in a big way with the flow of water going into Pakistan,' he says. 'But we don't know. There has been a build up to this from 2016, which has led to this situation.'
Unprecedented escalation
While India and Pakistan have always been at loggerheads, Prime Minister Modi's decision to suspend the treaty marks an unprecedented escalation.
Over the decades, the water treaty became one part of a complex network of written and unwritten understandings that regulated relations.
The 1972 Simla agreement formally froze the line of contact in Kashmir where the two sides had stopped fighting following the Indo-Pakistan War, which raged a year earlier and resulted in the creation of Bangladesh.
The two armies, while regularly shelling one another, established hotlines. Generals would invite one another across the frontline to go duck shooting.
When the Telegraph visited the contact line in 2019, a Pakistani officer explained that we were in view of Indian snipers who had only recently opened fire but predicted with confidence there would be no fighting that day.
'If you look over there, you will see they have visitors too today.' Sure enough, on the other side of no-man's land, a small group of what were presumably Indian journalists could be seen peering curiously in our direction.
This level of coordination should not be romanticised. The grim logic of nuclear deterrence – India got the bomb in 1974, Pakistan in 1998 – has been at least as important as the water treaty in dampening the desire for full scale confrontation.
But on the whole, the conflict has been relatively well regulated. The fear now is that all those safeguards could come tumbling down.
'They've been at it for such a long time, and there are certain rules of engagement. Now those rules of engagement are being questioned,' says Bajpaee.
'Back in 1999 both countries went to war in Kashmir, but the Indian military response was so restrained they refused to send fighter aircraft across the border into Pakistan-administered Kashmir. That has all changed under the Modi government. In 2016, they carried out strikes in Pakistan-administered Kashmir. And in 2019 they conducted air strikes in Pakistan proper.'
Still, he says, there are some limits notionally in place. Water is one. 'These are lines that, essentially, can't be crossed.'
Water wars
When it comes to using water as a weapon of war, says Michel, 'the Indus has long been on the radar.' But it is far from alone. 'The usage of water management as a tool of geopolitical leverage has been an emerging challenge.'
The most infamous water conflict is in the Jordan river valley, where so much water has been syphoned off that the river is little more than a trickle by the time it reaches the Dead Sea.
The Nile is another example of upstream dependency, with Sudan and especially Egypt almost entirely dependent on rains that fall on the Ethiopian highlands.
In the Tigris and Euphrates system, Syria and Iraq have both accused Turkey of using its control of the headwaters to exert political pressure. At one point Turkey and Syria signed an explicit conflict-related water deal - Turkey promised to release more water to Syria if former leader Bashar al-Assad ceased backing the PKK, a Kurdish insurgent group.
In the Mekong river system, meanwhile, China has been building hydroelectric infrastructure both on its own portion and in that of neighbours like Laos and Myanmar – to the alarm of Vietnam, Cambodia, and Thailand.
India, at large, is itself a downstream nation. The Brahmaputra river, in the country's east, rises in China and is vulnerable to an enormous hydroelectric project planned by Beijing.
The parallel has not been lost on some Indian newspaper commentators, who have cautioned against setting a precedent by holding Pakistan's rivers hostage. It might be best not to give China, a Pakistani ally, any ideas.
'Pakistan is in a spot – its dams only hold about 30 days flow of the Indus. In the dry season Pakistan is heavily dependent on having managed its water resources. That is the chokehold on Pakistan's economy,' says Michel. 'So it is a point of leverage. And that is reflected around the world.'
'It is a combustible mixture of hydrology – where the water comes from – with politics and trust. Look at the Rhine or the Rhone. Dynamics differ because of the trust between those countries.
Until recently people would have said the same about relations between the US and Canada over the Columbia river – it's not the Indus or the Mekong or the Nile.
But last month, Donald Trump suspended negotiations over the 61-year-old pact which governs the river – including its transnational flood control, power generation and water supply.
'The concern is the Trump administration could use this pause in the context of larger tensions between the US and Canada as a source of leverage,' says Michel.
The lesson is simple. Where there is strife, water conflict soon follows.