As the contradictions of Asia’s water challenges have been laid bare this summer—with millions affected by flooding while others are hit by droughts—one thing has been made clearer: the coming water crisis could exacerbate already simmering domestic and regional tensions.

Heavy monsoon rains have produced the worst flooding in Pakistan’s history, with more than three weeks of flooding leaving at least 1,500 dead and more than 4 million homeless. Millions of Pakistanis already require humanitarian assistance, yet the likelihood that many more could be added to this list has grown with the announcement that 200,000 have been evacuated as flood waters continue to rise in Singh Province in the country’s south.

Meanwhile, flash floods and mudslides have submerged some villages in China’s Gansu Province, killing hundreds and leaving more than a thousand missing. Today, Chinese state media announced 250,000 had been evacuated in the north of the country after the Yalu River burst its banks.