Just when you think you’ve seen it all, out comes another Donald Trump tweet, or tweetstorm, to prove you wrong. On Sunday morning, America’s forty-fifth President, having just returned to Washington from the G-20 summit in Hamburg, Germany, pronounced his trip “a great success for the United States.”

It says something about Trump’s grip on reality that he could reach such a conclusion after a summit in which he and the rest of the U.S. delegation were utterly isolated on major issues such as climate change and international trade. In fact, the only way that German Chancellor Angela Merkel’s diplomatic sherpas were able to cobble together a communiqué that everyone could sign onto was to include a section that noted America’s decision to withdraw from the Paris climate accord, but which added, “Leaders of the other G20 members state that the Paris Agreement is irreversible.” The symbolism here was powerful: in a global forum that the U.S. government, especially the Treasury Department, helped to create during the late nineteen-nineties, Trump’s America stood alone.

Of course, the G-20 is far from perfect: the protesters assembled outside the Messehallen Convention Center, most of whom were peaceful, were right about that. The organization’s membership is arbitrary—Italy is a member, Spain isn’t; South Africa is in, Nigeria is out—and its pronouncements can reflect the sometimes hidebound thinking of finance ministers and central bankers. But the G-20 is also one of the few political forums for tackling global economic problems, such as financial contagion, tax evasion, and climate change (which is ultimately a market failure). And, until Trump’s election, U.S. leadership was widely recognized as an integral part of any G-20 get-together.

The message of Hamburg was that Trump’s “America First” rhetoric—and his inability to see international agreements as anything other than zero-sum deals—have changed that situation, at least temporarily. The rest of the world hasn’t turned its back on the U.S.; the country is still far too big and powerful for that to happen. And, in any case, many foreign leaders harbor respect for the values that the U.S. espouses and the global order that it has helped maintain for seven decades. At the moment, however, they are looking for ways to work around Washington and its rogue President.

Judging by his Twitter comments on Sunday, Trump is proud of having turned the U.S. into a G-20 pariah. But even more revealing, and disturbing, was the readout he delivered on his meeting last Friday with Russia’s Vladimir Putin. Here it is, not quite in its entirety (as, since we’ve heard Trump criticize Barack Obama and the “fake news” media many times before, I’ve left out those bits):

I strongly pressed President Putin twice about Russian meddling in our election, He vehemently denied it. I've already given my opinion. . . . We negotiated a ceasefire in parts of Syria which will save lives. Now it is time to move forward in working constructively with Russia! Putin & I discussed forming an impenetrable Cyber Security unit so that election hacking, & many other negative things, will be guarded . . . and safe. Questions were asked about why the CIA & FBI had to ask the DNC 13 times for their SERVER, and were rejected, still don’t . . . have it. . . . Sanctions were not discussed at my meeting with President Putin. Nothing will be done until the Ukrainian & Syrian problems are solved!

In the spirit of generosity, it should be acknowledged that the final sentence here was a welcome one. And Moscow’s many critics in Congress will surely remind Trump of it if he decides, during the coming months, to relax the restrictions that the Obama Administration imposed on Russia following its annexation of Crimea.

But the rest of what the President wrote on Sunday was a mess of confusions and contradictions. Trump didn’t out-and-out confirm the claim made by Sergey Lavrov, Russia’s foreign minister, that he had accepted Putin’s denials of any Russian involvement in hacking during the election. But Trump made perfectly clear that he still rejects the view of the U.S. intelligence community that Russia was responsible for hacking and that, for policy purposes, he considers the matter to be closed. Any effort to get to the bottom of what happened—much less impose some real punishment on Moscow—will be subjugated to the imperative of “working constructively with Russia.”

That brings us to the nuttiest part of the tweetstorm, perhaps the nuttiest thing an American President has said in decades: the proposal to create a joint “Cyber Security unit” with Moscow to safeguard future elections. Whether Trump himself came up with this ingenious proposal, or whether it was Putin’s idea, the Tweeter-in-Chief didn’t say. But it drew instant ridicule from both sides of the political divide.

“It’s not the dumbest idea I have ever heard but it’s pretty close,” the Republican senator Lindsey Graham told NBC’s “Meet the Press.” Representative Adam Schiff, the top Democrat on the House Intelligence Committee, said on CNN, “If that’s our best election defense, we might as well just mail our ballot boxes to Moscow.”

What was Trump thinking? As ever, we have to consider the possibility that he wasn’t thinking at all, and what he says doesn’t mean anything—not even when he is reporting on his dealings with the leader of a rival nuclear power. “Donald Trump is a man who craves power because it burnishes his celebrity: to be constantly talking and talked about is all that really matters,” Chris Uhlmann, the political editor of the Australian Broadcasting Corporation, said, in remarks about the G-20 summit that went viral. “And there is no value placed on the meaning of words, so what’s said one day can be discarded the next.”

The other reading is a darker one, and it involves taking Trump at his word. For whatever reason, he still appears to see Putin as a potential partner—maybe even one who can be trusted with some of America’s most sensitive secrets, such as the workings of its voting systems. If this is indeed the case, it matters little whether Trump is a Russian dupe or a Russian stooge: he needs to be stopped.

On Sunday night, Trump disavowed part of what he had said earlier in the day, writing in another tweet, “The fact that President Putin and I discussed a Cyber Security unit doesn’t mean I think it can happen. It can’t-but a ceasefire can,& did!” This message illustrated Uhlmann’s point about the half-life of Trump’s utterances, and also confirmed the truth of the Australian journalist’s over-all conclusion about the President’s trip to the G-20 meeting: “So what did we learn? We learned that Donald Trump has pressed fast forward on the decline of the United States as a global leader.”