FORT IRWIN, Calif. -- In the dusty California desert, U.S. Army trainers are already using lessons learned from Russia's war against Ukraine as they prepare soldiers for future fights against a major adversary such as Russia or China. The role-players in this month's exercise at the National Training Center speak Russian. The enemy force that controls the fictional town of Ujen is using a steady stream of social media posts to make false accusations against the American brigade preparing to attack. In the coming weeks, the planned training scenario for the next brigade coming in will focus on how to...