At the very start, Canadian Energy Minister Marc Lalonde wants you to know that while the Canadian energy policy may be "perceived" as anti-American, it is really a policy that treats all foreign investment alike.

What Lalonde is talking about is the program announced last year by Prime Minister Pierre Trudeau to "Canadianize" the energy industry, so that no more than 50 percent will be foreign-owned by the end of this decade.

This has become an emotional issue between the two great nations -- and trading partners -- of North America. About 72 percent of the Canadian energy industry is now foreign-owned. And about 80 percent of that foreign ownership is American. Since 57.6 percent of the Canadian energy industry is therefore in American hands, it is not totally unreasonable to view this particular Trudeau effort as aimed principally at Americans.

On the other hand, when viewed from a Canadian perspective, the goal is not illogical. Every "two-bit country" in Africa and the Middle East, Lalonde is quick to remind, already has asserted itself this way.

As the principal originator of the energy nationalization policy, Lalonde is an aggressive and sometimes touchy spokesman. The whole core of a defensive attitude endemic to many Canadians well up as Lalonde snaps: "There are too many American businessmen who have considered this country as being the 51st state for too long."

Anybody who looks at the Canadian situation objectively, he continues, "cannot but conclude that these are very moderate measures, and that if the Americans were in the same situation, they would have acted a long while ago, along something of the same lines."

There is emotion on the American side, too. It shows in what may be a congressional overreaction to Canadian proposals for takeovers of American industry. Some congressmen charge that these "raids" have been financed through special bank loans condoned, if not arranged, by the Canadian government -- a charge strongly denied by the Canadians, who point out that all banks in the country (except the central bank) are private.

But the Reagan administration is taking little for granted. Trade ambassador William Brock's office has begun a study to see if retaliatory measures are warranted. Even if nothing happens, that's a sign of difficult times ahead.

Lalonde gives his views at a dinner in the Parliament building for a group of correspondents, mostly Americans, who were in Ottawa for the recent trade summit. For the past century, Lalonde explained, foreign firms have been "coming into Canada and buying everythng that was available on the market until we introduced the Foreign Investment Regulation Act to ensure a minimum of control" on the amount of foreign investment.

"Quite clearly," Lalonde says, "our view is that the oil and gas sector is a strategic one for this country, and no country worth its salt in modern times would tolerate the degree of foreign ownership and control that exists in the Canadian petroleum industry, where last year over 80 percent in sales and 72 percent of the assets were foreign-owned, and where 17 out of the 25 largest corporations were foreign-owned and controlled, and where not one of the first 10 corporations was a Canadian-owned and controlled company."

So what Canada has done, ruffling American feathers in the process, is take steps to make sure that by 1990, those figures in the aggregate come down to no more than 50 percent. Canadian firms will get tax benefits and exploration privileges not available to others. Thus, market forces will push many companies into the mold of Canadian ownership.

Foreigners wonder whether the Canadian fears about hefty outside ownership reflect a real threat to the well-being of the Canadian economy and its citizesn, or whether the Trudeau-Lalonde "Canadianization" drive represents a nationalistic fervor with deeply embedded protectionist overtones. rIn other words, what difference does it make whether 51 percent of the stock of an energy company is in the hands of Canadian nationals, compared with say 49 percent?

Lalonde's answer is that Canada has made "a sound economic, a sound business decision" in its own best national interest. He draws an analogy with Canada's current struggle with England to be master of its own constitution. The time has come for a mature country to say, "'Thank you very much, but enough is enough -- I think we can walk on our own two legs.'"

Lalonde continued: "In the area of oil and gas it's a feeling that this is a strategic section that has known a great deal of growth in the last six years and will know more growth in the next 20. And if we want to be in a situation where we will not even have a larger area of our economy under foreign control over the next 20 years, we have to move now. And that's all it is. It is not a surge of Canadian nationalism, which says, 'Out with the Yankees.' It's just saying it's about time we should do what every other industrialized and every two-bit country in Africa or the Middle East has done. And look around, and the United States has done it 75 years ago."

What troubles the U.S. business community is the uncertainty of where the Canadian government may move next in its nationalization program. Lalonde says that since Canada is a large country, with a small population and a desire for fast growth, "we will continue to need foreign investment for a long time. But there are sectors that are judged key, and where foreign ownership has been judged excessive, and therefore we would like to take steps over a period of time to reduce that degree of foreign ownership and enlarge Canadian ownership."

Lalonde and other Canadians profess to be a bit stunned by the American reaction to steps they describe as necessary to make sure Canadians can control their own destiny. The energy minister grants that there is an ever-present fringe of xenophobic feeling in Canad, but he thinks Americans are wrong to take "assertiveness" in national energy policy as put forward by Canada -- or Mexico for that matter -- as evidence of anti-Americanism.

Canada wants to be a partner and ally of the United States, Lalonde assures, but "we just don't want to automatically subscribe to whatever the American policy dictates. And as I say when I read this Texas oil man saying, 'What are you going to do about that socialist government you've got in Canada?' -- that's none of his business."

Lalonde also brushes off the suggestion from a journalist that he has a chip on his shoulder, arguing that Americans he sees are more nationalistic than he is. As for the idea that the Canadianization drive may prove to be counterproductive to Canadian-U.S. relationships, he has a ready answer: "If we can't get the 50 percent ownership, we can give up this country."