Two old nation-friends are quarreling. Marie-Josee Drouin and Harald Malmgren write: ''Relations between Canada and the United States have become more strained than at any time in recent memory.''
The most contentious issues are economic. President Reagan and Prime Minister Pierre Trudeau are far apart in their economic philosophies. Mr. Reagan believes in limited government and the removal of restraints on private enterprise. Mr. Trudeau is liberal-left, a fan of socialist economist John Kenneth Galbraith, and regarded in Canada as no friend of business.
Apparently, one source notes, the two leaders have something of a personality clash. Reagan, as Canadians see it, is an American American, an ex-actor, lighthearted and vaguely anti-intellectual. Trudeau is a French-speaking intellectual, intense, and a keen Canadian nationalist.
Such differing thought patterns mix poorly. It may make it more difficult for the two leaders to deal with solid US complaints over Canada's new National Energy Program, the expanding role of Canada's Foreign Investment Review Agency, and other efforts of Canada to discriminate against outsiders (primarily American) in favor of Canadians. Canadians have their ''beefs,'' too.
''The two governments seem to be on a collision course, in a context that political leaders cannot fully control,'' warn authors Drouin, executive director of the Hudson Institute of Canada, and Malmgren, a Washington economic consultant, in an article in the current issue of Foreign Affairs.
Since this article was written months ago, Canada and the US have dealt with at least one troublesome conflict. They referred the dispute over the Gulf of Maine maritime boundary to an international tribunal for a binding settlement. The disputed area includes the valuable fishing grounds of Georges Bank.
Moreover, the Canadian budget of Nov. 12 contained no new Canadianization measures.
But in a message to President Reagan at that time, Trudeau did not rule out further such measures later in the budget year. Some in the Canadian Cabinet would like to see most of Canada's basic resources, including oil, controlled by Canadian private enterprise or the government.
American diplomats would not be surprised to find such sentiments in developing countries. They are also accustomed to a certain amount of Canadian nationalism. But recent Canadian actions have been a shock.
Irate American businessmen have been complaining to Congress, and a few hearings on Canadian issues have been held or scheduled. Said one Senate staff member recently: ''I don't think Canada can assume anymore a sympathetic ear in Congress. Canada is looking out for itself. Canada can expect us to do the same. We are not anti-Canadian. We are pro-American.''
There is some irony in the situation. During his election campaign, President Reagan spoke of his ambition to establish a North American common market. Anyone familiar with the Canadian scene knew the idea had no chance of being carried out. English Canada in particular has historically struggled to differentiate itself from the United States - not unify with its southern neighbor. French Canada, with its separate language and culture, has felt less threatened by American television, radio, printed material, and other influences.
Instead, President Reagan's task will be to prevent the Canadian-US relationship from deteriorating further toward some economic tit for tat. There's some talk of an end to the ''special relationship'' between the two nations.
At the moment, the US sees some Canadian actions as contraventions of the international trade and investment rules.
For instance, as a result of provisions in Canada's new National Energy Program that favor Canadian companies, several American oil companies have sold their Canadian oil operations to Canadian concerns. Some of these US companies felt they were in effect forced to sell at too low a price. Others, including Americans, say the fairness of the price will be determined by future trends in oil prices.
Whatever, the US faces what Drouin and Malmgren call ''painful dilemmas'' in dealing with Canada. Harsh rhetoric about Canadian unfairness would fan the flames of Canadian nationalism. Cooling the language risks sending the signal that all is well, when it is not, and encouraging other watching nations to violate international rules.
The two authors suggest the creation of a joint Canada-US economic commission to formalize the process of dealing with bilateral economic problems. It would consist of respected political and public figures, businessmen, labor leaders, and economists. Also, representatives of the Cabinets of both nations should form a joint committee to prevent day-to-day conflicts from becoming crises.
''Something has to be done,'' Mr. Malmgren notes.