"After Trump called NATO obsolete (then proceeded to walk that back), Europe was looking for public support of Article 5, which affirms that NATO members will come to the mutual defense of any member that is under attack. ...Trump could not even bring himself to utter explicitly that the U.S. supports Article 5 in his remarks at Brussels, which every single U.S. president has done since Harry Truman in 1949."
" reports surface that British police are withholding intelligence from the United States after leaks to U.S. media about the Manchester bombing investigation, and weeks after Trump revealed highly classified information to the Russians about operations against the Islamic State."
"For all of Trump’s fire and fury about the United States getting the raw end of the deal from NATO, from an optics standpoint, it is the United States that is looking like the irresponsible partner."

would that the worse thing was his personal taste in Christmas trees...
Article 25 isn't about trees...