As a kid, I had trouble understanding why my parents and siblings lived in Montreal and the rest of my family – grandparents, aunts, uncles, cousins – were scattered across the United States. On long car trips to visit relatives in New Jersey and Pennsylvania, my parents would tell us about the Vietnam war, and the thousands of US peace activists who, like us, snuck across the border to Canada in the late sixties.

I was told that the Canadian government not only stayed officially neutral during the war, it offered sanctuary for US citizens who refused to fight in a war they believed was wrong. Derided as “draft dodgers” at home, we were welcomed in Canada as conscientious objectors.

My family’s decision to emigrate to Canada was made before I was born, but these romantic stories planted an idea in my head when I was far too young to fend it off: I believed that Canada had a relationship with the world that was radically different from that of the United States; that despite cultural similarities and geographic proximity, more humane and less interventionist values guided our dealings. In short, I thought we were sovereign.

Ever since, I have searched for evidence to back up that childhood (some would say childish) belief – with no luck. Until last week, when Canadian foreign policy took its sharpest turn away from the US since the Vietnam War.

As it was in the sixties, Canada’s position on this US invasion is filled with hypocrisies. We have 31 soldiers in the Gulf who are serving on exchange alongside US and British troops, as well as three warships in the region. These, Prime Minister Jean Chretien says, are there as part of Canada’s support for the old model “war on terror,” not the new model war on Iraq, even if the former has been officially re-launched as the latter (we’ve never been ones to keep up with the fashions). But the remarkable fact remains: after decades of following the US into every major military campaign, Canada is not backing this war. “If you start changing regimes, where do you stop?” Mr. Chretien asked.

Equally remarkable has been Mexican President Vicente Fox’s position. Though also couched in caveats, he too has clearly stated “we are against this war.”

These mild, cautious, even ambivalent rejections don’t seem particularly spectacular set against the political bombast coming from Europe, China and much of the Arab world. And yet Canada and Mexico’s decisions may well represent a far greater challenge to a marauding American Empire than all the shouting coming from overseas.

After all, when European and Arab countries take on the US, it’s almost expected – but Canada and Mexico? We are more than friends, more than strategic allies. We are satellite states, extensions of the US, its front and back yard, supplying cheap labour (Mexico) and cheap energy (Canada), and of course, unconditional support. We are supposed to be on the same team – Team NAFTA.

And that is what makes the fact that Canada and Mexico are standing up to the US on the war – albeit while trying not to draw too much attention to ourselves – so significant. Empires need colonies to survive, countries that are so economically dependent, so militarily inferior, that independent action is unthinkable.

Solidifying and deepening these fears and dependencies among the US’s closest neighbours and largest trading partners has been NAFTA’s great achievement. The numbers speak for themselves: 86 per cent of Canada’s exports and 88 per cent of Mexico’s exports go directly to the US If the US retaliated against us by closing its borders, the economies of Canada and Mexico would crash overnight. With those stakes in mind, John Ibbitson, writing in this paper last week, railed against the audacity of Canadian MPs who dared question the legality of Bush’s attack on Iraq. “If you are one of the millions of Canadians whose job depends on the free flow of goods and services with the United States, you should be furious.” In other words, let the Europeans have their high-minded ideas about international law – we have just-in-time car parts to deliver.

And yet somehow, despite our extreme economic dependencies, despite our fear of retaliation, a strong majority of Canadians and Mexicans support our governments’ opposition to the war. This courage didn’t come overnight – we earned it, one Bush administration slight at time.

After September 11, Washington abruptly dropped plans to legalize the status of millions of undocumented Mexicans working without any protections in the US, a blow that seriously damaged Mr. Fox’s popularity at home. And rather than Canadianizing the Mexican border, the US has opted instead to Mexicanize the Canadian border. For Canadian citizens born in one of the countries the US considers a threat, entering the US has become an exercise in humiliation, complete with routine photographing and finger printing.

There is another factor leading to the newfound courage: it’s easier to risk trade relations when “free trade” policies, after failing to deliver on so many of their promises, are increasingly unpopular. Last week, the Washington Post reported that while Mexico’s trade volume has nearly tripled since since NAFTA was signed, poverty has surged drastically, with 19 million more Mexicans living in poverty than twenty years ago.

Now that Mexico and Canada have decided to declare their independence on Iraq, something remarkable is happening: nothing. No retaliation, not even a backlash – just an expression of “disappointment” from the US ambassador to Canada. Maybe they’re too busy French-bashing to even notice.

And this is the real significance of the Canadian and Mexican positions. All Empires, no matter how mighty, are also weak: awesome power disguises rapacious need, a carefully hidden dependency on the colonized for everything from resources to labour to land for military bases.

As the US’s most loyal lackies tentatively stand up to it one by one, we cannot help but notice that we are not just needy but needed. Canada and Mexico may seem expendable on their own, but combined? That’s a different story. Together, Mexico and Canada represent 36 per cent of America’s export market. We supply the US with 36 per cent of its net energy imports and 26 per cent of its net oil imports. And as much as its leaders like to imagine otherwise, the US is actually not an island. It shares 12,000 kilometers of borderland with Canada and Mexico which it cannot protect without us.

Maybe these numbers were never supposed to be added up. NAFTA was never really a three way partnership: it was more like two bilateral trade deals that were slapped together: one between the US and Canada, the other between the US and Mexico. That is beginning to change as the reality dawns that while the US may act like an island, dependent on no one, it lives in a neighbourhood. Abroad, the US may well be able to sail to military victory but at home, it suddenly finds itself surrounded.

So while Europe warns of the rise of a new age of imperialism, what we are witnessing in North America is, ironically, the opposite: a superpower’s surprising vulnerability, as dependent as it is dangerous. It may be able to live without the United Nations, it could probably make do without France. But the US could no more protect its people economically and physically without the help of Mexico and Canada than it could secede from Planet Earth.

The implications of that realization will be far reaching. Because there can be no all-powerful empires without faithful colonies.

This article first appeared in The Globe and Mail.