More than six decades ago, the world’s most generous ^[1] water-sharing pact was concluded. Under the Indus Waters Treaty ^[2], upstream India left the lion’s share of the waters from the subcontinent’s six-river Indus system for downstream Pakistan. But repeated Pakistani efforts to use the treaty to disrupt ^[3] India’s efforts to safeguard its own water security have driven India to rethink its largesse.

Last month, India issued notice ^[4] to Pakistan that it intends to negotiate new terms for the treaty. In its current form, the treaty permits ^[2] the World Bank to refer any India–Pakistan disagreement to either a neutral international expert or a court of arbitration in The Hague. But India contends that Pakistan, with its repeated bids for international intercession to block modestly sized Indian hydropower projects over technical objections, has abused and even breached ^[5] the treaty’s dispute-settlement provisions.

India’s frustration intensified last October when the World Bank appointed ^[6] both a neutral expert and a court of arbitration, under two separate processes, to resolve differences with Pakistan over India’s Kishenganga and Ratle hydroelectric projects in Jammu and Kashmir. India claims that the arbitral court proceedings, which began two days after it issued its notice to Pakistan, contravene ^[7] the treaty, so it is boycotting them ^[8]. The World Bank, for its part, has acknowledged ^[9] that ‘carrying out the two processes concurrently poses practical and legal challenges’.

India’s renegotiation plan—which focuses on barring ^[10] third parties from intervening in bilateral disputes under the treaty—appears to be a direct response to these developments. But, as India well knows, Pakistan is highly unlikely to agree to negotiations. This suggests that India’s recent notice to Pakistan is just its opening gambit. The next step may well be an attempt to force Pakistan’s hand on its long-term sponsorship ^[11] of cross-border terrorism.

This has been coming for some time. Six years ago, after an attack ^[12] by Pakistan-based terrorists on the Indian military in Jammu and Kashmir killed 19 troops, Indian Prime Minister Narendra Modi declared ^[13], ‘Blood and water cannot flow together.’ In a sense, his statement got to the heart of the treaty, which India pursued precisely to improve relations with Pakistan and avoid bloodshed on the subcontinent.

When the treaty was signed in 1960, Sino-Indian tensions ^[14] were high, so India effectively attempted to trade water for peace with its other large neighbour, Pakistan. The treaty—under which India keeps less than 20% ^[15] of the total basin waters—is the only international water agreement embodying ^[16] the doctrine of restricted sovereignty, with the upstream country agreeing to forgo significant use of a river system for the benefit of its downstream counterpart.

But the deal appeared only to whet Pakistan’s appetite for the Indian-administered region of Jammu and Kashmir, through which the largest three rivers of the Indus system flow. Five years later, in 1965, Pakistan launched a surprise war ^[17]—the second conflict between the two countries over the region’s status.

All the while, the treaty guaranteed ^[18] to Pakistan a huge share of Jammu and Kashmir’s water—the region’s main natural resource. This hampered economic development, led to chronic electricity shortages, and fuelled popular frustration in that territory. And when India attempted to address the region’s energy crunch by building run-of-the-river hydropower plants—which are permitted by the treaty, and would not materially alter transboundary water flows—Pakistan did everything it could to block progress ^[19].

Ironically, Pakistani officials and lawmakers have sometimes issued their own calls to renegotiate the treaty. In 2016, for example, the Pakistani Senate passed a resolution ^[20] to ‘revisit’ the treaty and ‘make new provisions’ that favoured Pakistan. But far from advancing Pakistan’s interests, such actions have merely reminded the Indian public that, at a time of growing water stress ^[21], the treaty is an albatross ^[22] around their country’s neck.

To be sure, Pakistan has plenty of its own water-related problems. A deep divide has emerged between downriver provinces and the upriver Punjab province, which appropriates the bulk of the Indus waters to sustain its profligate agricultural practices. Punjab’s water diversion—aided by large China-backed dams ^[23] in the Pakistani portion of Kashmir, including the massive Diamer Bhasha Dam ^[24]—is turning the Indus Delta into a saline marsh, which represents a major ecological disaster ^[25].

But none of this is the fault of the treaty, which is clearly in Pakistan’s interest to safeguard. To do that, Pakistan must stop focusing only on its treaty-related rights, while neglecting its responsibilities ^[18]. This includes rethinking the use of terrorism as an instrument of state policy ^[26]—a tactic that runs counter to the spirit of the treaty and threatens to drive India unilaterally to withdraw from it.

Such action would not cause river flows to Pakistan suddenly to stop, as India lacks the kind of hydro infrastructure this would require, and has no plans to change that. But it would enable India to pursue reasonable hydro projects without dam reservoirs, regardless of Pakistani objections. More fundamentally, it would sever a crucial diplomatic thread between India and Pakistan.

For any treaty to survive, the advantages it confers on all parties must outweigh the duties and responsibilities it imposes. The Indus Waters Treaty is nowhere near meeting that standard for India, which has so far accrued no tangible benefits from it. What has been called ^[27] the ‘world’s most successful water treaty’ has overwhelmingly benefited Pakistan, which has a powerful incentive to abandon its combative approach and embrace the compromise and cooperation needed to save it.