David Emerson, the former minister of foreign affairs, is right to argue, in his interview with Steven Chase in today's Globe and Mail, that the "buy-American" threat to Canada's exports is a vivid reminder that a coherent framework is needed for Canadian-U.S. economic relations.
In the current fray, Canada must fight hard to protect its interests. Mr. Emerson's customs-union idea, by contrast, would take years to negotiate and implement, and cannot solve the immediate issues of iron, steel and other manufactured products, though it might eventually prevent future conflicts.
In the supply chains of many industries, the two countries are already so integrated that any hasty and ill-considered interference by Congress may do as much harm to the U.S. as to Canada.
Mr. Emerson says that Canada should be ambitious in pursuing a possible customs union. The term "customs union" can mean too little or too much. Uniformity of external tariffs is desirable in itself, but in an age when most of the obstacles to international trade are non-tariff barriers, it will not suffice.
Uniformity of foreign-trade policies is a sounder principle for deeper economic integration, but it is no easy matter to define what is and what is not a trade policy.
Much of all this comes down to the humdrum theme of harmonizing regulations. Such harmony cannot be total, however, short of a unitary North American state and loss of national sovereignties, which is not Mr. Emerson's point. Moreover, harmonization should not mean that weak policies prevail over strong ones (as if by a regulatory Gresham's law), or vice versa.
Rather, the policies that govern economic activities would normally be similar, without regard to vested, inertial interests in existing schemes. Cross-border regulatory differences would be based on well-considered, deep-seated policies.
Mr. Emerson draws a comparison to the European Union that is not wholly convincing. The customs union that evolved into the EU was based on a balance among rough equals, initially France and West Germany, and later Britain.
Given the large disproportion between the U.S. and Canada, the trilateral approach - including Mexico - proposed in a 2005 task-force report by former deputy minister John Manley and his colleagues, offers a way forward that Canadians need to think about seriously.