He quoted Roosevelt and gently greeted frail veterans at a D-Day commemoration, hours after proclaiming Bette Midler a “psycho” and Chuck Schumer a “creep.” He exalted soldiers’ bravery while dismissing his avoidance of service in Vietnam, calling it a country “nobody heard of.” He toasted Britain’s queen at a Buckingham Palace banquet, after calling London’s mayor a loser…

The president arrived in Europe embracing a number of positions that are anathema to many of the people he encountered. But he pivoted abruptly when he found resistance, underscoring that his approach is less ideological than transactional and situational, and sowing confusion about what, exactly, is Mr. Trump’s bottom line.

He insisted that Britain’s public health system needed to be part of any trade negotiation with the United States, but then swiftly took it off the table. He likened the idea of a hard border between Northern Ireland and the Irish Republic, after Brexit, to his border wall with Mexico, but then agreed with Ireland’s leader, Leo Varadkar, that there should be no wall dividing north and south.