Two weeks ago, President Trump publicly told North Korean leader Kim Jong Un “don’t worry about it” when Mr. Kim was asked about the release of Otto Warmbier — the young American who had been imprisoned in North Korea and died just weeks after he was released from that jail. At a press conference before flying to China, Mr. Trump said Mr. Warmbier’s death and the fact that it happened while he was President of the United States “was going to be very hard on him.” He added, “I hope it’s going to be a very good thing for him.” His critics were all kinds of miffed — including Richard N. Haass, who argued that Trump had signaled “he would have done differently.” He was, in the end, proven right, as Mr. Warmbier’s release was re-announced following an effusive phone call between the president and the North Korean ruler on Wednesday.

We can argue over Mr. Trump’s handling of this episode, but what is beyond dispute is that his comments were, in retrospect, the one serious error of the recent record in terms of his foreign policy. That is because it illustrated two things about this president. One is that he is self-absorbed and shows no sense of where U.S. and international interests — both domestic and foreign — intersect. The other is that he is arrogant. He was not apologetic for his recklessness, and he had no interest in hearing a persuasive argument from those on the other side. His was a mentality of inflexibility and rage, which he has displayed in his dealings with his opponents and perceived enemies. But it was on display once again in his remarks about North Korea’s transfer of Otto Warmbier to the United States.