Transboundary rivers: geography trumps treaties in water control

Control of transboundary rivers hinges on geography rather than legal frameworks. While treaties and international principles govern shared waterways, upstream nations possess tangible power through dam construction and water management infrastructure. China's hydropower projects on the Yarlung Tsangpo, which enters India as the Siang and eventually becomes the Brahmaputra, exemplify this dynamic. India lacks a binding river-water treaty with China to regulate such construction.

India's position reverses on the Indus, where it sits upstream of Pakistan. The 1960 Indus Waters Treaty provides detailed water-sharing arrangements. Following the 2025 Pahalgam attack, India placed the treaty in abeyance, suspending cooperation mechanisms including data sharing and commission meetings—though lacking infrastructure to completely cut water flow. A Hague tribunal ruled India could not unilaterally suspend the treaty; India contested this decision and the arbitration process itself.

The core challenge remains unresolved: existing treaties were designed for routine water management, not geopolitical crises involving cross-border attacks and terrorism. Geography ultimately determines practical control over shared river systems.