When Allies Become Imagined Foes: Behind Canada's First Simulation of a U.S. Invasion in a Century

On January 20, 2026, Canada's *The Globe and Mail* disclosed a piece of news that shook the international relations community: the Canadian military had secretly developed a response model to address a potential military invasion by the United States. This marks the first time since the late 19th century that this founding member of NATO has formally and systematically designated its southern neighbor—its closest ally and defense partner—as a potential military threat for theoretical exercises. The report emphasizes that this is not an operational plan but rather a conceptual and theoretical framework. However, the mere existence of the model itself speaks volumes.

The news emerged as former U.S. President Donald Trump posted an AI-generated image on his social media platform Truth Social: against the backdrop of the Oval Office, an American flag on a map covered Canada, Greenland, and Venezuela. This is not the first time Trump has made similar remarks. Since being re-elected and taking office in 2024, he has repeatedly publicly stated that Canada should become the 51st state of the United States and questioned Canada's ability to defend its Arctic territories. These statements, along with his open coveting of Greenland, are creating a rift of trust within the North Atlantic Alliance.

For over a century, the US-Canada border has been regarded as the world's least fortified boundary, symbolizing unparalleled trust and integration between the two nations. Today, however, the Canadian military is seriously discussing how to use guerrilla tactics akin to those of the Afghan Taliban to resist the overwhelming force of the US military. This shift is far from a simple military exercise; it reflects the shaking foundations of the international order in the post-Trump era and the struggle of a middle power to redefine its security position under the shadow of a superpower.

From "Brotherly Nations" to "Potential Threat": The Collapse of Trust

The history of U.S.-Canada relations is almost a chronicle of shared defense and deep integration. The two countries share the world's longest international border, jointly operate the North American Aerospace Defense Command (NORAD), and have deeply intertwined military, intelligence, and economic ties. Canadian soldiers have fought alongside American troops, from Normandy to Kandahar. In the eyes of the vast majority of Canadians and Americans, the possibility of armed conflict between the two nations is akin to science fiction.

However, political rhetoric possesses the power to reshape reality. Trump's remarks—whether originally intended as serious geopolitical assertions or as performances to incite domestic populism—have crossed a red line. By treating the territory of sovereign states as tradable or annexable assets, this mindset fundamentally overturns the international order based on sovereign equality and rules. For Canada, this is no longer an occasional trade dispute or policy divergence among allies, but a potential challenge to the very foundation of its national survival.

The anonymous senior officials cited by The Globe and Mail admitted that although they believe the likelihood of Trump actually ordering an invasion is extremely low, the strategic posture under the Trump administration requires a new risk assessment. At the core of this assessment lies a profound uncertainty: when the world's most powerful nation is steered by a capricious leader who disregards traditional alliances, any assumptions based on historical trust are no longer reliable.

What is even more unsettling is the shift in public sentiment. A public opinion poll in the summer of 2025 revealed that, for the first time, a majority of Canadians view the United States as the greatest threat to their country. This dramatic change in perception has provided the government with domestic political space, and even a necessity, to conduct such sensitive exercises. The military must be prepared for the deepest fears of the populace, if only to provide reassurance.

"Asymmetric Warfare": The Defensive Logic of the Weak

According to leaked model details, the Canadian military's wargaming is based on a stark realist premise: in a conventional war, Canada stands no chance of winning.

Based on deduction and estimation, the U.S. military has the capability to destroy or occupy all of Canada's key strategic locations, including major cities, ports, and military bases, within 2 days to 1 week. Canada has fewer than 70,000 active-duty military personnel and relies heavily on U.S. military technology and intelligence support, with its defense budget being only a fraction of that of the United States. As a former Canadian strategic planning director once said: We cannot resist the world's most powerful military.

Therefore, the model's focus shifted from how to win a war to how to make an invasion unbearable. Its inspiration is directly drawn from classic cases of modern asymmetric conflicts: the Mujahideen resistance against the Soviet Union in Afghanistan in the 1980s, and later the Taliban's tactics against U.S. and NATO coalition forces. The core idea is to abandon decisive frontal battles and instead launch a nationwide, protracted guerrilla warfare and resistance movement.

This asymmetric defense concept encompasses several key elements:

National Resistance and Large-Scale Reserves: The model explores the possibility of mobilizing over 400,000 volunteer reservists. Not all of these personnel would be integrated into the regular military; some may serve as armed civilians or irregular military personnel, conducting sabotage, reconnaissance, and harassment activities behind enemy lines. This echoes Ukraine's successful experience in mobilizing national resistance during the early stages of the 2022 war.

Guerrilla Warfare Combined with High Technology: The tactical combination includes both traditional ambushes, sabotage, and hit-and-run harassment, as well as modern elements. Retired Major General David Fraser pointed out that Canada could follow Ukraine's example by extensively using drones and anti-tank weapons to inflict sustained casualties on occupying forces. The goal is to cause large-scale casualties to the U.S. occupying forces and make the cost of maintaining the occupation unbearably high.

Utilizing Geographical Depth: Canada is the world's second-largest country by area. Its vast wilderness, complex coastlines, and frigid Arctic regions present a logistical nightmare for any occupying force. The model suggests that even if the capital, Ottawa, were captured (similar to the Russian military's attempt to capture Kyiv), it would not signify the nation's surrender. Instead, it could mark the beginning of a prolonged, bloody, and politically disastrous war of occupation.

Seeking External Assistance: The model assumes that once the United States invades, Canada will immediately seek help from other nuclear powers, particularly the United Kingdom and France. An official stated bluntly: If you attack Canada, you will face opposition from the entire world... You might see German warships and British aircraft appearing in Canada to reinforce the country's sovereignty. This scenario rapidly internationalizes a bilateral conflict, potentially triggering a broader alliance confrontation.

Warning Signals and Strategic Dilemmas: A Three-Month Window

The practical significance of the model lies not only in how to fight, but also in when to know that a fight is necessary. Canadian military planners are attempting to identify the precursors of an invasion.

The clearest warning signal would be the United States unilaterally withdrawing from or undermining the cooperation framework of the North American Aerospace Defense Command (NORAD). NORAD is the highest symbol of U.S.-Canada military integration, and its dissolution would signify a complete rupture of bilateral defense relations. Model estimates suggest that from the emergence of a clear warning signal to a potential invasion, Canada would have, at most, a preparation window of three months.

The next three months will be a frantic race against time: urgently mobilizing reserves, evacuating critical facilities, dispersing military assets, stockpiling supplies, and sounding the alarm to the international community. The narrow time window highlights Canada's lack of strategic depth when facing its giant southern neighbor.

However, the paradox lies in the fact that while the military conducts such simulations, the daily cooperation between the U.S. and Canadian forces continues as usual. Reports indicate that the two militaries are even jointly planning Canada's participation in the missile defense system proposed by Trump. This split state of peacetime cooperation and wartime simulation epitomizes the complexity of current U.S.-Canada relations: operational-level professional ties remain strong, but strategic-level political trust has developed significant cracks.

Greenland's Shadow and the Arctic Game: A Larger Geopolitical Puzzle

To comprehend Canada's anxieties, one must not view the U.S.-Canada relationship in isolation but rather place it within the broader geopolitical landscape of Trump's second term, particularly the competition surrounding the Arctic.

Trump's public interest in Greenland is not an isolated incident. He believes this Danish autonomous territory holds crucial value for U.S. Arctic defense and resource extraction, and has even hinted at using force to acquire it. This move has already sparked strong backlash from European allies, with France and Germany deploying troops to Greenland in a show of solidarity. Canadian Prime Minister Mark Carney has also made a clear statement: On the issue of Arctic sovereignty, we firmly stand with Greenland and Denmark, fully supporting their unique right to determine Greenland's future.

The Greenland incident sets a dangerous precedent. It demonstrates that within Trump's transactional worldview, the sovereignty of allies can be re-evaluated and bargained over. If the United States can lay claim to Danish territory in the name of national security, could similar thoughts arise regarding Canada's vast and strategically important Arctic region? Trump's recent complaints that Canada poses a problem for its Arctic defense undoubtedly deepen such concerns.

Therefore, Canada's military exercise is both a direct response to Trump's annexation rhetoric and a preventive hedge against the uncertainty brought by his entire diplomatic philosophy. It sends a signal: even in the face of the most powerful ally, Canada will never automatically retreat on issues of sovereignty.

Conclusion: An Elegy for the Old Order and a Prelude to the New Reality

The Canadian military's simulation of a U.S. invasion holds far greater symbolic significance than its military value. It serves as an elegy for the old order—the rules-based, liberal international order underpinned by U.S. hegemony and basic trust among allies—now facing the most severe challenges since the Cold War.

In January 2026, at the World Economic Forum in Davos, Canadian Prime Minister Mark Carney delivered what the media called an epic speech. He began by stating clearly: Today, I will talk about the fracture of the world order—the end of a comfortable narrative and the beginning of a harsh reality. He asserted that the old order will not return, waiting for others to fix it is futile, and nations must work together to build a new order that is more just, resilient, and sustainable.

Canada's military model is a concrete manifestation of this harsh reality in the field of national defense. It signifies a fundamental shift in the strategic thinking of Canada—and perhaps many traditional U.S. allies as well—from absolute reliance on American protection toward strategic autonomy that prioritizes self-preservation in an era of uncertainty.

Almost all military experts interviewed believe that a U.S. invasion of Canada remains an extremely low probability event in the foreseeable future. However, as Aisha Ahmed, a political scientist at the University of Toronto, stated: The more Canada embraces this mindset of homeland defense, the lower the likelihood that all these terrible scenarios, which no one hopes will happen, will become reality.

The purpose of the simulation is not to predict war, but to prevent it. By demonstrating the bloody, protracted, and global consequences that an invasion would bring, Canada aims to raise the threshold and cost for any potential aggressor. In this sense, this seemingly pessimistic military model ultimately serves to maintain peace—except that it no longer naively assumes peace comes from eternal friendship, but rather from sober awareness and steadfast preparation.

When Canada began seriously considering how to use guerrilla warfare to resist the U.S. military, the world had already changed. This is no longer the familiar, predictable century we once knew. Nations, regardless of size, must recalibrate their compasses amidst turbulent waves.