Tit for tat -- OR, Children know this game

U.S. Defense Secretary Jim Mattis on Tuesday criticized what he called a destabilizing Russian military build-up near Baltic states and officials suggested the United States could deploy Patriot missiles in the region for NATO exercises in the summer.  U.S. allies are jittery ahead of war games by Russia and Belarus in September that could involve up to 100,000 troops and include nuclear weapons training -- the biggest such exercise since 2013.  Reuters