The G7 summit has ended in acrimony, with US President Donald Trump lashing out at host Canada and retracting his endorsement of the joint statement. …Until just a few weeks ago, the relationship between Mr Trump and Mr Trudeau could have been called cordial. Despite differences between the two countries over trade – over everything from lumber to the major renegotiation of the North American Free Trade Agreement – the two men tended to speak positively about each other. No longer. The recent US decision to impose metals tariffs on Canada, the EU, and Mexico was a turning point. Mr Trudeau began using a much harsher tone. Polls indicate Canadians support the tougher stance. …Whether or not this new phase in the Canada-US relationship will allow some of the trade sticking points to be resolved is still to be seen.