WASHINGTON—The World Trade Organization’s (WTO) Appellate Body handed down a decision in the 14-year-old Airbus subsidy case that upheld previous rulings that launch aid on the A350 and A380 programs was improper, but also took enough alleged subsidies off the table to allow Airbus to claim a measure of victory. Nevertheless, the appellate ruling left about $9 billion in subsidies in play that the European Union (EU) will have to account for as the U.S. moves to seek authority ...