The American president recently started fixating on the line separating the United States and Canada. It’s worth asking why.

Canadians and Republicans alike are confounded as President Donald Trump increasingly links a trade war to his push to annex America's northern neighbor.

Statistics Canada writes that the number of Canadians returning to the United States by car went down 23 percent in February.

Trump thinks about Canada in much the same way Vladimir Putin thinks about Ukraine. He identifies with his fellow imperialist ...