Stephen Handelman, author and journalist, writes the biweekly TIME Canada column and is a frequent commentator on North American and international affairs. We cannot accept unpaid the sheltering protection of another state. -Stephen Leacock, 1909TWO YEARS AFTER THE TERROR ATTACKS on the World Trade Center and the Pentagon, North America is a profoundly divided continent. Canada, Mexico and the United States have achieved a level of security co-operation that would have been unthinkable a few years ago, but the lingering sense of vulnerability in the region's most powerful nation continues to influence, and in some cases distort, the politics of the region. The solidarity and common vision that accompanied the signing of the 1994 North American Free Trade Agreement (NAFTA) have been undermined by the opposition of America's northern and southern neighbours to its war in Iraq. Moreover, Washington's troubled and potentially long-term occupation of that faraway Middle Eastern country raises doubts about whether it can sustain the momentum (or interest) for the broadened hemisphere partnership promised at the outset of George W. Bush's presidency. Meanwhile, although the huge trade flows that made the region an engine of world prosperity in the 1990s have resumed, trade and social policy conflicts have sharpened as economic uncertainties have begun to eat away at consumer and investor confidence. With increasingly divergent views on foreign and economic affairs, on security threats, and on their obligations to each other, the three nations have rarely been so far apart.Arguably, the Canada-US relationship, in particular, has suffered the most bruising blows. The sophisticated social, economic and political linkages across the 49th Parallel made it easier for Canadians to move towards the new security condominium demanded by Washington. If nothing else, the deepening integration of the two economies (and the common vulnerabilities arising from that integration) made such a partnership a matter of obvious self-interest for both countries. Yet Canadian suspicion of American policies, coupled with American resentment of Canadian softness in foreign and military policy, has diminished the possibilities for a genuine political dialogue that would rise above technical discussions over border controls and customs harmonization. Such a dialogue is even more crucial now as the two countries move from tackling border security to the thornier issue of continental defence.The framework for dialogue is certainly there. North America changed shape on 12 December 2001. On that date, Canada's then foreign affairs minister John Manley and Tom Ridge, the former Pennsylvania governor who had become director of the new US Office of Homeland Security, met in Ottawa to give their governments' formal approval of a 30-point Smart Border Action Plan--hurriedly worked out by officials of both countries in the aftermath of the attacks that had taken place, almost to the day, three months earlier. A similar (though considerably less ambitious) agreement was signed between the US and Mexico on 22 March 2002. Both plans were in some ways extensions of the NAFTA agreement in that they created a system of co-operative vigilance at the borders that would enable the benefits of the trade pact to continue.The 30 points of the Canada-US plan, which would later be expanded to cover other forms of commercial and agricultural trade, included measures for joint policing and customs inspection that would incorporate the latest innovations in scanning technology and data sharing. But the agenda, in Canada's case at least, was about far more than the border. Manley and Ridge declared that their aim was to create a zone of confidence in which citizens of both countries could continue to trade and interact inside a new protective security shield.It may have sounded modest, but this was a transforming proposal. …