While a U.S. invasion seems the stuff of science fiction, it feels disturbingly lower on the fantasy scale than six months ago.

An Environics poll of more than 2,000 Canadians in April 2025, reported in the Globe & Mail, found that 43 percent believed an attack  by the United States within five years was at least somewhat likely. Ten percent deemed it highly likely or certain.

Expressing a similar view, 81 percent of 3000 Canadian opinion leaders interviewed between January and June 2025 voiced concern about the US military threat and believed that Canadians must be prepared to make sacrifices in resisting Trump.

Thinking the Unthinkable

Many Canadians may reluctantly conclude that an invasion of Canada cannot be dismissed as ridiculous. It is unlikely, but it is still a contingency that we should be prepared for. And the better prepared we are, the more unlikely an incursion.

Consider the grounds for concern:

• Trump in his inaugural address stated that his administration would “expand our territory” and “carry our flag into new and beautiful horizons.”. He has, many times, called for the annexation of Canada as the 51st state.
• Few critics, six months ago, would have thought that Trump would have moved so far toward his goal of personalist authoritarianism so quickly. This record shows his ability to move fast. It should be a warning to Canadians who value their independence.
• Trump, since assuming the presidency for a second term, has appointed personally loyal heads of the defence department, the CIA, the FBI, and national intelligence. He has purged the upper ranks of the armed forces of officers who might resist unlawful commands. Trump has thus positioned himself so that the US armed forces will fall into line with his dictates.
• Officials in Trump’s administration have claimed that Canada is a security threat. Both FBI Director Kash Patel and Homeland Security Director Kristi Noem have referred to Canada as a hotbed of terrorist threats. Trump has imposed tariffs on Canada, including the recent 35 percent tariff on non-CUSMA-compliant exports, partly on the grounds of Canada’s alleged (and unsubstantiated) failure to control movements across its border. Some right-wing influencers, such as Ben Shapiro, suggest the US claim Canada –  in Shapiro’s comment, as a territory, like Puerto Rico. (Lacking voting rights, an annexed Canada could not then deliver an overwhelming vote against the Republicans).
• Canada is in a weak position vis-à-vis the United States. This weakness may encourage Trump to intervene. Canada cannot expect its NATO allies to do more than protest a US invasion. Much of the Canadian army is integrated with the US forces in North America’s defence. US arms manufacturers provide much of Canada’s weapons and, in some cases (such as the F-35 aircraft), control computer updates, as well as repairs and ammunition. This military dependency is in addition to America’s well-known economic leverage, and lesser-known control – via the Internet bros in Silicon Valley – of Canada’s digital infrastructure.

The government of Mark Carney has the difficult task of reducing these vulnerabilities – in short order.

Watching for Signals

If Canadians accept that there are grounds for concern, what signs of an impending attack should we be tracking?

• The rhetoric of Trump and his acolytes (including Republican Internet influencers) concerning Canada and Canadians: Is it becoming increasingly vituperative? Are Canadians characterized as untrustworthy, unwilling to pull their own weight on military defence, receptive to migrants with bad intentions toward the USA? Lax in the regulation of the Canada-US border? If a terrorist plot  is allegedly concocted in Canada, Trump might regard it as  grounds for invading Canada.
• ·The emergence of more fake front organizations using disinformation to ridicule Canadian resistance and exacerbate regional divisions within Canada.
• Covert interference in Canadian elections, and an increase in US spying activity in Canada·
• Surreptitious US support for separatism in Alberta (which may already be underway) and perhaps Quebec (though in Quebec, unlike Alberta, separatists tend to be social democrats, not MAGA).
• The United States takes over Greenland, and perhaps the Panama Canal. Canada, as the toughest case for annexation, can expect to be dealt with last.
• A major shortage of fresh water in key “red” states of the United States, prompting the president to demand turning on “the Canadian tap”. Trump might regard the Canadian refusal to acquiesce in supplying ample fresh water as justification for readjusting the border by force.

Moving from Weakness to Strength

If our best defence is a united and resolute people, that adage provides little comfort. Canadian national identity is not strong. Not only do we have separatist movements in Alberta and Quebec, but also younger Canadians are more pessimistic about our united future and more open to American annexation than other generations. In an Ipsos poll in January 2025, four in ten Canadians aged 18-34 indicated they would vote to be Americans if the US guaranteed them citizenship and conversion of assets to US dollars. In Alberta, the governing MAGA-like United Conservative Party is itself flirting with separation from Canada. We have work to do.

Little wonder, then, that several commentators have recently urged the expansion of  voluntary national service. Some argue for three or four voluntary agencies; others only for a rejuvenated and enlarged Civil Defence Corps. These agencies would build and mobilize our skills and talents, as well as fortify networks of public trust and community.

These nation-building ventures are important. But they do not answer the question few dare to pose: how would Canada respond to a (still unlikely) American invasion? A military response? That would be highly destructive and probably ineffective. But we should not equate “defence” solely with “military defence.”

Counter-intuitively, nonviolent civilian defence is our most effective, and least costly response. A million Canadian volunteers, trained in nonviolent resistance, could paralyze and demoralize an expeditionary force, while sparking widespread nonviolent protests in the US and denunciations of the US action worldwide.

Conclusion

But that is a large and separate topic. The message here is that, yes, we must take Trump’s annexation threats seriously, and yes, we can identify signals that an incursion is becoming more likely.

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