Parts of India are on track for severe water shortages, according to results from Nasa's gravity satellites.
The Grace mission discovered that in the country's north-west - including Delhi - the water table is falling by about 4cm (1.6 inches) per year.
Writing in the journal Nature, they say rainfall has not changed, and water use is too high, mainly for farming.
Through two wars and a half-century of suspicion and resentment, the Indus Waters Treaty has governed the sharing of a strategic river between the bitter nuclear rivals eager to control and to profit from it. But will India and Pakistan's treaty survive the emerging water crisis?