Russia will stage its largest war games since the fall of the Soviet Union next month, the country's Defense Ministry said Monday. Thousands of troops from China and Mongolia are expected to join in the exercises in Siberia, dubbed Vostok 2018, according to statements from the Russian and Chinese defense ministries. The games will have an "unprecedented scale both in territory and number of troops involved," supreme commander-in-chief of the Russian armed forces, Gen. Sergi Shoigu, said in a statement. Shoigu said it would be the "largest event since the Zapad-81 maneuvers," which involved as many as 150,000 troops. If...