More than six decades ago, the world’s most generous water-sharing pact was concluded.

Under the Indus Waters Treaty (IWT), 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 India’s efforts to safeguard its own water security have driven India to rethink its largesse.

Last month, India issued notice to Pakistan that it intends to negotiate new terms for the IWT. In its current form, the treaty permits 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 the IWT’s dispute-settlement provisions.