Trump's latest threat of a 50% tariff on the European Union, starting June 1, comes after what he calls a "very difficult" time of negotiations, which are "going

nowhere." And there may be some important reasons behind this. According to FHN Financial's Chief Economist Chris Low, the EU, made up of 27 countries, "wants to negotiate

trade with the U.S. as a bloc, but the individual EU countries cannot agree on terms and have not ceded negotiating power to Brussels." Low added: "It is possible the threat of a

higher tariff will prompt more serious negotiations, but it is no guarantee."