Don't repeal Murphy's Law

IF Peter O. Murphy, an American, were to walk down the street in downtown Toronto, the odds are that many Canadians would recognize him. If he did the same thing in Boston he could be unknown. Who's Peter Murphy?

He was the special negotiator for the United States in its free-trade talks with Canada. The legal text of the agreement was finally released last Friday, about 200 pages long, with an additional 600 pages of ``tariff elements.'' This pact will govern the world's largest and most complex trading and economic relationship - presuming Congress and Parliament approve.

Because Canada ships some 80 percent of its exports to the US and because the American relationship is so important to Canada in general, Mr. Murphy with his bushy shock of red hair was a common sight on Canadian television within the last year while the deal was being negotiated. In the US, which sends 20 percent of its exports to Canada, television and the press have paid far less attention to this pact. Nonetheless, the free-trade arrangement with Canada represents in its own way as bold and constructive a foreign policy achievement of the second Reagan administration as the newly signed disarmament deal with the Soviet Union.

For the next several months, Murphy will be busy trying to convince Congress that the free-trade arrangement is good for the United States. We certainly believe it is. It will eliminate most tariffs between the two countries over 10 years, starting next year. It will remove many other impediments to commerce. It will assure the US of a supply of needed Canadian energy - oil, gas, electricity. It should boost living standards on both sides of the border.

Though undoubtedly some businesses and their employees may not enjoy the new competition, free trade, as Murphy put it recently, ``is not a zero-sum game.'' Each side will benefit.

Should special interests manage to persuade enough members of Congress to vote against the pact to kill the deal when it comes up for debate and a vote in the new year, it would be sad. Another 20 to 40 years could pass before a Canadian government might again take the enormous political risk of talking with the US about free trade. It would be a major opportunity lost.