Read: Trump’s national-security report card

Heading into the four-day trip, the president appears squarely focused on the domestic scandals that his predecessors seemed only too happy to escape. That much was clear from his recent trip to Tokyo, where Trump toasted the new Japanese emperor at a banquet in the Imperial Palace. At different moments in his stay, he mocked Democrats for considering impeachment; tweeted that he “smiled” when the North Korean dictator Kim Jong Un insulted his potential rival in the 2020 election, Joe Biden; and boasted that he’d weathered Special Counsel Robert Mueller’s Russia investigation. “No obstruction, no collusion, no nothing,” Trump said at a news conference, standing beside his host, Japanese Prime Minister Shinzo Abe.

“I try to imagine how leaders of other countries might see the U.S. through President Trump,” Representative Joaquin Castro, a Democrat who serves on the House Foreign Affairs Committee, said in an interview. “And they see a scattered mind.”

After returning home from Japan, Trump’s fixation only appeared to grow. Mueller made a rare televised appearance to discuss his findings and say his work was done. White House Press Secretary Sarah Sanders put out a statement saying Mueller had gotten on with his life and everyone else should do the same. One person who won’t let it go: her boss. Talking to reporters on Thursday, Trump rehashed an eight-year-old dispute in which Mueller asked to have his membership fee refunded at Trump’s golf club outside Washington. Why that matters now—or ever—wasn’t clear. His anger swelled as he talked about the prospect of impeachment: “A dirty, filthy, disgusting word,” he said.

Such is the president’s mood on the eve of a trip meant to commemorate victory over the fascist powers. Making matters more combustible, Trump is at odds with his own foreign-policy team. He undercut his national security adviser, John Bolton, during the Tokyo trip, publicly disagreeing with him over whether recent North Korea missile tests ran afoul of United Nations resolutions.

When he lands in London on Monday, Trump will also be walking into a tense regional political environment where nationalist-populist forces are jockeying for power with more centrist groups. Trump symbolizes a nationalist wing hostile to immigration and focused on sovereignty. He has talked privately of pulling out of NATO, and upset many European leaders by withdrawing from the Paris climate agreement. He has also criticized European Union trade practices. Taken together, Trump’s moves have threatened the multilateral consensus that has underpinned European security since the Second World War.

A belief inside some European capitals is that Trump is merely an aberration. Once he’s gone, the thinking goes, the next president will repudiate the brand of unilateralism that this one has championed. But Trump could be in the job through the end of 2024, depending on how elections go. In the meantime, Europe is still learning how to live with America’s impertinent president.