A dry path of Indus River in Jamshoro and Kotri district in Hyderabad in Pakistan on May 6. Pakistan almost entirely depends on the Indus river system.

A dry path of Indus River in Jamshoro and Kotri district in Hyderabad in Pakistan on May 6. Pakistan almost entirely depends on the Indus river system.

Photographer: Jan Ali Laghari/Middle East Images/AFP/Getty Images

Explainer

Why This River in India and Pakistan Is Causing So Much Angst

The suspension of a water-sharing agreement in place for 65 years signals a new low in relations between the nations.

A major river system that flows through both India and Pakistan has been a source of ongoing tensions between the two countries for decades. But India's unilateral suspension in April of a water-sharing agreement that's been in place with Pakistan for 65 years signals a new low point in relations.

India paused the Indus Waters Treaty within 24 hours of an attack in the disputed region of Kashmir on April 22 that killed mostly Indian tourists, for which India blames Pakistan. Pakistan has denied the allegations. The move by India to pause the treaty came as a surprise, especially as the pact — signed in 1960 — had previously managed to withstand multiple conflicts. However, India’s dissatisfaction over some of its clauses, which it says are outdated, as well as Pakistan’s frustration over India’s hydropower buildout on the rivers, have been brewing for the past decade.