At 2.09 am on Saturday, Ahmad Subhan, who lives near an air base in the Pakistan military garrison city of Rawalpindi, heard the first explosion that rattled the windows of his house - and took South Asia to the brink of war.

India's decision to suspend the treaty marks a significant diplomatic shift. Pakistan depends heavily on these rivers for agriculture and civilian water supply. "Water cannot be weaponised," Pakistan's Finance Minister Muhammad Aurangzeb told Reuters news agency on Monday, adding that "unilateral withdrawal has no legal basis".

India also has a long-standing policy of refusing to allow foreign mediation when it comes to the status of Muslim-majority Kashmir - a disputed region claimed by both India and Pakistan in its entirety - which has been at the center of the latest conflict with Pakistan and which India regards as a strictly internal matter.