His nutty behavior is bad enough at home; it’s even worse abroad when he is supposed to be representing not just his rabid base of “deplorables” but, rather, the whole country. That is something Trump simply does not know how to do.
Thus, in the course of this trip, he trashed his predecessor, the U.S. intelligence community, and the “fake news” media. Can you imagine Ronald Reagan in 1981 going abroad and attacking Jimmy Carter for not doing more to stand up to Soviet aggression? Or attacking the press for being hostile to him in the 1980 campaign (as they were) and the intelligence community for not predicting the Iranian revolution (as they did not)? It’s unimaginable, yet Trump somehow thinks that it’s appropriate.