Trump’s latest phone negotiation tactic on tariffs likely to heighten EU retaliation threat

President Trump’s Friday flurry of pronouncements marks the return of negotiation by smartphone and may trigger another period of profound uncertainty for international trade and financial markets. The threat of 50% tariffs against the European Union, issued hours before his trade representative met their European counterparts, is a show of presidential muscle surely designed to strongarm those on the other side of the table. It is an escalation likely to heighten the threat of retaliation from Europe, and with a few keystrokes ends the brief period of calm that had returned to global trade and markets in recent days. Money…