I'm a Canadian foreign policy expert. Donald Trump is a threat to my country's national security

It is sobering to think that, in less than a week, the United States may begin an ominous shift from Canada's closest and most important ally to one of our most serious national security challenges. For the first time in more than a century, when Canadians think of the country most likely to adversely affect their safety and well-being, their eyes may turn south.

This is not exaggerated partisan rhetoric. Donald Trump is hostile to NAFTA — the foundation of our current bilateral trading relationship — and equally critical of the broader international trade regime. Canada-US trade employs millions of people and is equal to almost 40% of Canadian GDP. A erratic, protectionist Trump Administration would put that economic relationship at risk....
http://www.businessinsider.com/trump-danger-canadian-national-security-2016-11