President Donald Trump spent years promising to make Mexico pay for a wall at the US southern border. Mexico did not. In a strange twist, Trump is now threatening to block the opening of a bridge at the northern border that Canada actually already paid for. This is either next-level negotiation or a misunderstanding of the facts, or both, but an ultimatum Trump made on social media is the latest in a string of erratic moves that have confused his fellow world leaders. The Gordie Howe International Bridge is basically completed Trump should have previously known that the brand-new Gordie...