At the remote, mountainous frontier where the mighty Mekong carves the border between Myanmar and Laos, planners have sketched the outline of a mega dam. It would be the largest hydropower project ever built on the river’s mainstream outside China, but analysts suspect the study into it may matter more than the dam itself. A 34-month joint feasibility study for the 2,790-megawatt project was agreed on July 4 during Myanmar President Min Aung Hlaing’s state visit to Vientiane. Officials from both...