Senator Mark Warner became exasperated Tuesday with Trump Trade Representative Jamieson Greer as he was unable to give a real answer as to why the president hit Australia—a key ally with whom the U.S. has a trade surplus—with 10 percent tariffs on all imports. “Australia is one of our strongest allies…. We have a free trade agreement with Australia. We don’t have tariffs,” Warner said. “We have a trade surplus with Australia…. With a trade surplus, with this strong relationship, Australia got