The controversial Dakota Access pipeline has been halted for now. The Army Corps of Engineers denied a permit for the oil pipeline to pursue a route near the Standing Rock Sioux Reservation, amid protests from the tribe, which was worried about potential water pollution. But other groups, such as opponents to fossil fuel, hoped to thwart the project as part of a bigger strategy. They’re trying to delay new pipelines and other fossil-fuel infrastructure projects until renewable energy sources can be competitive.