The US has a problem on its northern border too

Since the 1970s, Canada has cultivated a reputation for having one of the most liberal immigration systems in the world, with a strong emphasis on diversity. But the country’s unique, decades-old immigration consensus is being eroded. Prime Minister Justin Trudeau’s open-border approach has permitted unchecked immigration to thrive at the expense of economic stability, social integration and national security.

Acting on a tip-off from a European ally, the Royal Canadian Mounted Police...