Last weekend, while crossing the border back to Ontario from Buffalo, our car was stopped by a customs officer. "What were you guys doing in the States?" he asked. "Do any shopping?" "Okay, have a great day."

Nothing strange here, except for one detail: this man had a U.S. flag on his sleeve. He stopped every car before waving them on to Canadian border guards who repeated the process all over again. It felt like a glimpse into Fortress North America, a not so distant future in which U.S. security officers are the gatekeepers not just of the U.S. border but of the entire continent.

Post September 11, many Canadians see some border integration as the unavoidable price of protecting our $700-billion annual trade relationship with the U.S. Exports now make up 43 per cent of Canada's GDP, up dramatically from 25 per cent a decade ago. Eighty seven per cent of those exports go directly to the U.S. With almost half of our economy now directly dependent on an open border, it's difficult to see how Canada can stand up to U.S. pressure.

But as Monday's budget shows, Canadians are being asked to give up more than border control. We are also being asked to hand over a chunk of the economic dividends of years of economic austerity. Finance Minister Paul Martin's "security budget" throws $1.2 billions directly at the border. Some of it is designed to protect Canadians from terrorists, but much of it must be seen for what it is: a new public subsidy for multinational corporations.

When Canadians patiently accepted cutbacks to health care, unemployment insurance, and many other social programs, we were told that all this austerity was necessary to attract foreign investors. We weren't trading our social programs in exchange for free trade, the boosters said—on the contrary, only free trade would generate the kind of prosperity needed to rebuild our social programs.

Only there's a hitch. Just as Canadians were starting to imagine spending some of our recent national prosperity on new programs—restoring our commitment to foreign aid, for instance, or tackling child poverty—it now turns out that the budget surplus will not be used to make people more secure. It will to be used to make trade more secure, to "keep our borders open," as Mr. Martin said on Monday.

The proceeds of cross-border trade are going back into the border itself: to make it a terrorist-fighting and free-trade flowing super-border. We are going to have "the most modern border in the world," Mr. Martin enthused. This, it turns out, is the legacy of all the years of belt-tightening: not a better society, but a really great border.

The plan is to create multi-tier border crossings that are at once open for business but closed to "unwanted" people. This is no easy task, since migration of people and trade in goods tend to be closely interrelated. In global terms, many immigrants are people who have been displaced by trade, whether by industrial agriculture or mega-dams, which push many people off their land and send them across borders in search of jobs.

That's why Mr. Martin's to plan to open and close the border at once is so costly: $395-million to screen refugees and immigrants, $58-million to makes border crossing smoother for frequent business travellers, $500-million to crack down on illegal immigrants, $600-million over six years to improve the traffic flows, and so on.

Let's pause for the irony. Free trade was supposed to lower the costs of moving goods across borders, thereby encouraging new investment. Now we have become so dependent on trade (and the U.S. has become so mistrustful of our ability to police ourselves), that we are spending hundreds of million of new dollars just to keeping the trade flowing.

Put another way, costs that used to be absorbed by the private sector in the form or export and import duties and tariffs have been transferred onto taxpayers in the form of security costs. The border, the promise of so much prosperity, is turning into an economic sinkhole.

Annette Verschuren, president of Home Depot Canada, applauded Monday's budget, saying, "We depend on the border to ensure that our goods get to our stores and anything that speeds it up reduces our costs."

Are the new security costs an unavoidable price to pay for our economic stability? Perhaps. But they should at least send as a cautionary message to our politicians who are pushing to expand the North American free trade agreement into the entire hemisphere.

Free trade has already taken a severe toll on our social programs and our ability to make sovereign immigration and refugee policy. It is now costing us billions in security dollars. Can we at least stop calling it "free?"