Donald Trump’s first trip to Europe as president, back in May, was an unmitigated disaster. He scolded allies, publicly and privately, and shocked his own aides by refusing to affirm NATO’s Article V mutual-defense provision. The best thing that can be said about his return is that at least this time he did voice support for Article V. So give this trip a D rather than the F he earned the first time around.

Why not a higher grade? Because President Trump can’t help being himself, wherever he is. 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.

Just as he thought it was appropriate to tweet a bizarre attack on former Hillary Clinton campaign chairman John Podesta right before his meeting with Vladimir Putin. And to give up his seat at the G-20 meeting to his daughter Ivanka, as if he were presiding over a hereditary monarchy like Saudi Arabia. Or to dissent from the consensus of the other 19 nations in favor of the Paris climate accord. If this is “modern-day presidential,” as Trump claims, then please bring back pre-modern presidential — you know, the ancient, long-forgotten standards of decorum that prevailed until January 19.

Trump is not entirely devoid of any knowledge of the expectations that await him. He knew enough, at least, to raise the issue of Russian interference in our election with Putin, realizing he would be pilloried if he did not. There is no agreement about what Trump said, because, being paranoid about “deep state” leaks, he refused to have a note-taker in the room. Both Putin and his foreign minister, Sergei Lavrov, claimed that Trump “accepted” Putin’s assurances that Russia was not behind the hacking of the Democratic National Committee and the Clinton campaign. A U.S. official anonymously denied this, while Secretary of State Rex Tillerson claimed that Trump “pressed President Putin on more than one occasion regarding Russian involvement.”

Trump himself could clear up this disagreement in an instant if he would simply tweet that he did not accept Putin’s duplicitous denials of Russian involvement. Instead his tweet on the subject gave every indication that he had accepted Putin’s position — hardly surprising, when just the day before in Warsaw he had questioned Russian responsibility for this blatant interference in the U.S. election.

Of course, even if one accepts the Tillerson readout, the meeting was a big win for Putin because Trump did not threaten any punishment for Russia’s involvement in the 2016 election. Instead, according to Tillerson, “the two presidents, I think rightly, focused on is how do we move forward; how do we move forward from here.” Imagine FDR and Tojo meeting in 1942 and agreeing to move on from that little unpleasantry at Pearl Harbor. ...