Over the course of 1,800 miles, 5,300 vertical feet, and at least five name changes, the Brahmaputra River, in sometimes turbulent outbursts, flows from the Tibetan plateau to the Bay of Bengal. Along the way, it crosses three countries, including major geopolitical rivals China and India, and supplies 90 percent of downstream Bangladesh’s freshwater during the dry season.

Yesterday afternoon President Obama announced a new Presidential Memorandum on climate change and national security. The policy directs 20 federal agencies to consider the national security implications of climate change and establish a working group that will develop a Climate Change and National Security Action Plan for the federal government.

With the Sustainable Development Goals nearing their one-year anniversary, the global community continues to strive toward eradicating poverty by 2030. In order to achieve this ambitious target, many international development practitioners are embracing a more holistic approach to development, combining traditionally single-sector programming, like health or environment work, into more comprehensive efforts. But such integrated development is sometimes easier said than done.

Early this June, the Israeli government cut off drinking water to people living in the Salfit region of the West Bank and three villages east of Nablus. The consequences have been dire. Thousands of Palestinians have been left with no running water in their homes, and factories have been forced to shutter. The power imbalance that leaves Palestinians so vulnerable to Israeli turns of the valve plays out every year, made possible by Israel’s occupation of the water-rich Golan Heights in 1967. What is perhaps most surprising is that the situation persists.

A study published in PNAS highlights the unpredictability of the impacts of climate change on water resources by comparing detailed simulations in mountain areas of Chile and Nepal. Authors Silvan Ragettli, Walter W. Immerzeel, and Francesca Pellicciotti study the response of river flows to a significant decline in glacier areas in the Juncal catchment of Chile and the Langtang catchment of Nepal at higher spatiotemporal resolutions than any previous study.

Rivers have shaped the Western Balkan Peninsula’s characteristic landscape and played an important role in its history. Following the violence of the Yugoslav secession wars in the 1990s and the creation of six new nations, the number of transboundary river basins doubled from 6 to 13. In Kosovo, where independence remains a question, the water sector is a microcosm of tensions between ethnic Serbs and Albanians. The challenge of water resource management exists not only over the province’s contested national boundaries with Serbia, but between divided ethnic groups within the territory.

“The time for talk is done; it is now the time for action,” says Inger Andersen, director general of the International Union for Conservation of Nature (IUCN), in an interview before the 2016 World Conservation Congress.

The Nile River is shared by 11 countries, for which it is vital for food and energy production, freshwater, and as a means of transportation. Sharing the resources of the Nile has, however, been politically difficult. Recently, the construction of the Grand Ethiopian Renaissance Dam has caused a major dispute with downstream Egypt which fears the dam will affect water flow in its own territory.