Canada’s failed policies are doing more than fouling American air. Summer across the Midwest and East Coast has again brought unhealthy and hazardous air-quality warnings from Canadian wildfires. Poor forest management threatens public health and daily life. Canada’s immigration policies pose a deeper and more lasting danger.

Most Americans still regard Canada as a polite northern extension of the United States: familiar, friendly, and strategically harmless. That view belongs to another era. Canadian Prime Minister Mark Carney has said that “nostalgia is not a strategy.” Neither is complacency.

America once regarded the northern border as its safest frontier. That assumption is precisely what now makes it dangerous. Nobody thought to watch it.

Canada is becoming one of America’s most underestimated national security vulnerabilities: a permissive northern platform through which mass migration, organized crime, and hostile foreign influence can reach the United States.

The first problem is demographic. In 1961, 96.8% of Canadians reported European origins, primarily British or French. By 2021, that figure had fallen to 52.5%, a decline of 44.3 percentage points in 60 years, even allowing for changes in census methodology. Canada has undergone one of the most dramatic demographic transformations in the Western world. A mass-migration regime has shifted the primary source of new Canadians from Europe to Asia, with Asian populations now making up roughly one-fifth of the country.

That change would carry fewer risks in a confident, assimilationist nation. Canada has chosen the opposite course. The United States has historically shown an extraordinary ability to turn foreigners into Americans. Canada instead embraced state-sponsored multiculturalism. Former Prime Minister Justin Trudeau even described the country as the world’s first “postnational state,” with “no core identity” and “no mainstream.” Canada has combined mass immigration with an increasingly vague idea of national belonging.

Immigration without assimilation has accelerated the country’s Balkanization. New arrivals often settle in established immigrant communities, producing ethnic enclaves first at the neighborhood level and, increasingly, across entire cities.

In Brampton, Ontario, Canada’s ninth-largest city, more than 52% of residents are South Asian. In Richmond, British Columbia, more than half the population is Chinese. Markham, Surrey, Burnaby, Mississauga, and Richmond Hill reflect the same pattern: not merely high immigration, but concentrated communal geography.

Lebanon offers an extreme warning of where such politics can lead. Once politics stops revolving around competing ideas and becomes a census of rival communities, foreign governments learn to exploit those divisions.

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That prospect should concern Washington. Canada has already become a major arena for foreign interference. Its own public inquiry has examined the activities of China, Russia, India, and other governments. Diaspora communities can become targets and instruments of intimidation, surveillance, political coercion, and imported ethnic conflict. The 2023 killing of Sikh separatist Hardeep Singh Nijjar illustrated the danger. Canadian officials alleged that agents of the Indian government were involved in his assassination on Canadian soil.

China presents the gravest strategic threat. Beijing does not need to turn Canada into an outright enemy of the United States. It needs only to use Canada as a gateway into the North American system. During the 2025 campaign, Carney identified China as a major geopolitical threat and source of foreign interference. His government has since adopted a more accommodating posture, even avoiding a direct answer when asked whether he still regarded Beijing as a threat.

Canada’s decision to allow Chinese electric vehicles into the country at reduced tariff rates shows the risk. Modern electric vehicles are not simply cars. Their cameras, microphones, sensors, software, and remote-update capabilities can collect enormous quantities of data. Washington may restrict Chinese connected vehicles in the United States, but those safeguards weaken if Canada allows large numbers of them into the shared North American market.

That policy could put tens of thousands of Chinese surveillance platforms on American roads, gathering information near military bases, power plants, communications infrastructure, and other sensitive sites.

The physical border creates another vulnerability. The northern frontier no longer deserves its old reputation as strategically irrelevant. U.S. Border Patrol apprehensions rose sharply from fiscal year 2022 through fiscal year 2024, although they have since declined under the Trump administration.

The increase showed how easily weak Canadian migration policy can undermine American border enforcement. When the United States tightens its southern border while Canada maintains looser entry policies, the northern frontier becomes an escape valve for foreign nationals seeking unlawful entry.

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The danger extends beyond illegal immigration. Criminal organizations, foreign agents, and potentially terrorist-linked individuals can exploit a border designed around an older assumption of trust. Fentanyl compounds the threat. Authorities have intercepted Chinese precursor chemicals in Canada and uncovered sophisticated drug “superlabs” north of the border.

The conclusion should be unavoidable: The Canada of the American imagination no longer exists. The old Canada rarely sent toxic smoke across the border. It served as a loyal northern shield — a NATO ally, a NORAD partner, and a dependable member of the Western alliance.

The new Canada is more ambiguous and more dangerous. It remains formally allied and culturally familiar, but it is also increasingly fragmented, increasingly open to commercial ties with American adversaries, and increasingly exposed to hostile foreign influence.

The United States need not treat Canada as an enemy. But we can no longer assume Canada will remain a fully reliable security partner. America once regarded the northern border as its safest frontier. That assumption is precisely what now makes it dangerous. Nobody thought to watch it.