>>Hannah Beech, The New York Times Published: 11 Dec 2020 06:48 PM BdST Updated: 11 Dec 2020 06:48 PM BdST Vigilance against the coronavirus has been heightened in the Thai border town of Mae Sot, which sits directly across the Moei River from Myawaddy, Myanmar, on Sept. 28, 2020. The region depends on its porous crossings for economic activity, but countries have been quick to point fingers when the coronavirus has spread along shared frontiers. (Adam Dean/The New York Times) A casino in Myanmar that is frequented by Thais, who slip easily across the border, is viewed from across the Moei River in Thailand on Sept. 29, 2020. The region depends on its porous crossings for economic activity, but countries have been quick to point fingers when the coronavirus has spread along shared frontiers. (Adam Dean/The New York Times)