"You have to marvel at the mind-melting incompetence required to produce this outcome," Taylor wrote, noting Canada and the U.S. share the "longest peaceful border"on Earth, an integrated defense relationship, and a history of fighting alongside each other, with roughly "70% of Canadian exports" flowing to the U.S.

Taylor didn't hold back on Trump personally, calling him "the stupidest man" he believes has held office in Washington. He noted that even John Kelly, Trump's former chief of staff, has said Trump is "the most flawed person" he's ever met.

Taylor added that previously overseas ally officials used to quietly ask "whether America was still America" — but that they've "since stopped asking."