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".

Pakistani officials have said Saturday’s ceasefire with India reestablished deterrence. But New Delhi insists the rules of engagement have irrevocably changed.