The Globe and Mail reports in its Wednesday edition that why would Canada want to strike a trade deal with Mr. Trump: We did strike a trade deal with him just a few years ago, and he tossed it. Guest columnist Mark Johnson writes that a trade agreement with Canada would mean he gives up the ability to jerk us around. After all, his power is not only the tariffs, but the uncertainty itself, the very unpredictability of his actions that he lords over us. Madness is his method. The more uncertainty he creates, the more he advances his agenda. If our prosperity depends on a trade deal, it will only happen when Mr. Trump takes us seriously. Maybe Ontario Premier Doug Ford has the right idea with his surprise tactics: the ban on U.S. alcohol, the threat of cutting off electricity, the pro-free-trade Ronald Reagan advertisement. It sure got to Mr. Trump. Think unconventional trade combat. Other tactics could include targeted, high-impact tariffs on American goods that are implemented without warning, like soft drinks and processed foods. Mr. Trump isn't fighting like Prime Minister Mark Carney expects him to. Maybe Canada should be less conventional and more guerilla. It just might work. So far, the PM's strategy hasn't.