I assumed you had no point and that were you just parroting a headline, but to your "point", the reason for a wall along the Canadian border.
Drugs and terrorists coming from the southern border are much more an concern than Canadians or terrorists coming across from the northern border. That said the wall which costs 0.12% of the national budget or 1% of the military budget is just supposed to lessen the flow of people walking across our southern border unaccounted for. If it lessens the transportation of drugs or terrorist that would just be considered a welcome bonus.
Some actual numbers:
Distribution of Border Patrol seizures ALL substance
Southern Border: 1,555,552 lbs
(99%)
Eastern and Western Coastal Borders: 8,054 lbs (.5%)
Northern Border: 905 lbs
(.05%)
Nationwide Total: 1,564,511 lbs.
I'm guessing neither terrorists coming from Canada or brown people coming across to work for Trump are an existential threat, but I would chose terrorist in your red herring of a question.
Covered previously, but fewer than 800 people have illegally crossed from Canada into the U.S. annually over the past five years, compared to hundreds of thousands apprehended at the U.S.-Mexico border. If a terrorist wanted to be successful you would go with the 500k people walking across the southern border last year. And the border patrol says many crossers are from countries other than South America. So the concern that terrorists might attempt a crossing at the southern border is more than a scene in Sicario, which was great movie.
LINKY
I think the wall was one of a number of reasons people voted for him and I don't think they care who pays for it, but you are welcome to that opinion.
The Canadian invasion is real, lots of grape smugglers and banana hammocks.
Border Patrol swarm:
http://video-monitoring.com/beachcams/lakeworthinlet/pics/v18/feb1719a/f171404a.mp4
I have yet to hear one person point out that Trump asked for $800M in humanitarian aid at the southern border in his compromise... and Capitol Hill responded (with the deal that was just approved) by cutting that humanitarian aid by 50%.