MOSCOW—The Russian military will form 20 new units in the country’s west this year to counter what it claims is a growing threat from NATO. Defense Minister Sergei Shoigu made the announcement Monday at a meeting with top military officials. He pointed to a growing number of flights by U.S. strategic bombers near Russia’s borders, deployments of NATO warships, and increasingly frequent and massive drills by alliance forces. He charged that such actions “destroy the international security system and force us to take the relevant countermeasures.” “We will form another 20 units and formations in the Western Military District until the year’s end,” Shoigu said. He added the military units in Western Russia have commissioned about 2,000 new pieces of weaponry this year. Last month, a massive troop buildup in Russia’s south and southwest near the Ukrainian border raised concerns in Ukraine and the West, which urged Moscow to withdraw …