There's a flaw in this argument, of course, and I think you've spotted it: The exports of subsidized babies would surely be slapped with an unfair trade suit by the Surrogate Mothers of America. At any rate, it never happened, just as nuclear-tipped ICBMs were never installed on Baffin Island (one of Mel Hurtig's best), Smith & Wessons were never licenced for sale in corner stores, and so on: all the horrors we were told would befall us if ever we trucked with the Yankee trader.

But now a new and more ominous shadow falls across the border. We may have escaped the invasion of the baby-snatchers only to fall into the professionally trained clutches of . . . the chiropractors. At least, that's what a coalition of concerned citizens - well, a posse of self- interested unions, anyway - would like you to believe. If the provinces do not act fast, a flurry of news stories warned last week, the United States will use NAFTA to open large swaths of the Canadian health-care market to alien providers. Among the potential invaders: dentists, cosmetic surgeons, laundry services and, yes, chiropractors.

The language of these accounts suggests something on the order of the fall of Rome. "NAFTA flaws may open medicare to U.S. assault," wailed the headline over one story. "The provinces will be open to all sorts of attacks," a trade lawyer predicted in another. The Financial Post reported the same "fears." As yet, The Toronto Star has had nothing to say on the matter, which can only mean a six- part series is in the works.

The source of this latest media anxiety attack was the release of a legal opinion, commissioned by the Canadian Union of Public Employees, the Canadian Labour Congress and a galaxy of other groups representing Canadian health-care providers. The opinion, prepared by Professor Bryan Schwartz of the University of Manitoba, is a sound and sober review of the agreement's provisions on health care. It's the sponsors' interpretation of it that's out of line.

Under the original Canada-U.S. free-trade agreement, all existing restrictions on foreign competition in the service sector, including health care, were grandfathered, exempting them from the usual requirements of "national treatment": i.e. non-discrimination. In addition, NAFTA made room for the federal and provincial governments to add new restrictions. Under Annex II of the agreement, Canada reserved the right to declare whole industries off-limits, including "social services established or maintained for a public purpose," such as health care. Of course, "public purpose" leaves some latitude for interpretation. So, if they want to be certain of excluding the Americans, the provinces have to list the specific anti-competitive measures they wish to exempt. The deadline is March 31.

It's pretty hard to find an assault on medicare in any of this. The areas the legal opinion lists as possible targets of foreign competition are precisely those services that are not publicly funded: dentists, cosmetic surgeons and so on. No possible construction of "public purpose" could exclude health care provided out of public funds, which is to say medicare.

If, then, we are talking about purely commercial services, there are no more grounds to outlaw foreign competition here than in any other industry. If a Canadian seeks the relief that a chiropractor's knowing hands can grant, why should he not have his choice of domestic and foreign versions? What possible "threat" can this pose, except maybe of a sore neck?

It's probably true, as Prof. Schwartz warns, that doctors and clinics providing services that are covered under medicare, but operating entirely outside the system - that is, charging full fees - would be open to competition from U.S. providers. But so what? Canadians who are prepared to pay for private health care, in addition to the taxes they pay into the public system, can get it from Americans now, just by crossing the border. What's the difference if the Americans come to them? If anything, the added competition would be an incentive for those Canadian doctors to get back under the medicare umbrella.

The trickier question is whether services that were partly publicly funded (i.e. where extra-billing was allowed) would fall within the "public purpose" envelope, or whether discriminating against outsiders in those areas would run afoul of NAFTA. Perhaps we shouldn't let Americans offer services for public money - though if they can do it better and cheaper, it's hard to see why not - but the real threat to medicare in this scenario is the extra-billing, not the presence of foreigners. If we don't want the rich to buy their way to the front of the line for public care, we should be just as willing to ban them from going to Canadian doctors as Americans.