Japan’s export downturn entered a fifth straight month after a 2.4% year over year decline in April. An outlier has been trade with the U.S. where exports surged 9.6% including a 32.4% rise in chemicals shipments and an 83.2% jump in semiconductor equipment. The improved exports resulted in the largest trade surplus Japan has had with the U.S. since Dec. 2015 at $6.55 billion. That may cast a shadow over trade negotiations which are ongoing this week ahead of a summit meeting between President Donald Trump and Prime Minister Abe from May 25. One early, though pre-announced, win comes wit...