After watching the G7 train wreck aghast, senior officials at NATO headquarters are quaking in their boots at the prospect of hosting a summit of the Western defense alliance featuring a raging Donald Trump in Brussels. Far from showcasing transatlantic unity and resolve, they fear the 24-hour gathering of leaders of the 29-nation alliance, scheduled for about a month from now, could turn into round 2 of the rumble in Quebec, with the U.S. president on the rampage against the Europeans and Canadians over their allegedly unfair trade surpluses and puny military spending, leaving NATO in tatters.