Trump still doesn't understand how the European Union works. At the NATO/EU meeting, he criticized German export practices. When Merkel visited Washington, Trump claimed that the U.S. trade deal with Germany was so unfair and that he wanted to renegotiate the terms of that deal. Only problem — the U.S. doesn't have a trade deal with Germany. The EU is a trading bloc, and trade agreements are negotiated by the bloc, not by individual members. He made the same mistake when the Italian Prime Minister visited Washington. There was so much media coverage of that display of ignorance that you would think that he wouldn't repeat it. But this week, in Brussels, he once again exposed his ignorance.