In this week of debate on El Salvador, highlighted by President Reagan's call for more American involvement, I have been reading the wrong book. It is a newly published book about Canadian-American relations by Lawrence Martin, a reporter for the Toronto Globe and Mail, called "The Presidents and the Prime Ministers."

It is the wrong book because it is a vivid reminder of how stunningly blind we in the United States can be to the impact of our actions on those countries that fate put in our backyard. We have a hard time seeing ourselves as our neighbors to the north or south see us.

In describing what he calls in his subtitle "the myth of bilateral bliss," Martin tells some absolutely hair-raising tales of what American residents have done to Canadian prime ministers over the past century--all in their best interests, of course.

Here, for example, is Lyndon B. Johnson, having a diplomatic discussion with Lester Pearson up at Camp David, the day after Pearson had made a speech criticizing the American bombing of North Vietnam:

"Striding the porch, his arms sawing the air, his sulphrous vocabulary contaminating it, Johnson ripped into Pearson full- voltage. . . . Having pinned the much smaller Pearson against the railing, the President of the United States grabbed him by the shirt collar, twisted it and lifted the shaken Prime Minister by the neck. The verbal abuse continued in a venomous torrent. 'You p----d on my rug,' he thundered."

Afterward, when the two leaders met the press, they both described the session as "friendly." A decade elapsed before anything like a full picture of the episode emerged.

Martin writes that such camouflage is normal. "The U.S. Presidents and the Canadian Prime Ministers would meet more than 80 times. . . . Virtually all of the meetings, according to the public pronouncements, would be splendid successes. . . . Sometimes a 'new era of consultation' would be born, and it would be followed by another 'new era of consultation.' During each era, the Canada-U.S. discussions would always be 'open and frank,' and if they had that open and frank quality, there would be an excellent chance that a 'great rapport' would be established. The great rapport in turn would often lead to another 'historic agreement' serving to keep the 'undefended border' undefended."

And all the while, as Martin makes clear, presidents were delivering the most unbelievable insults to prime ministers, sometimes intentionally, sometimes not. The polished John F. Kennedy issued a press release contradicting Prime Minister John Diefenbaker's statements on joint defense issues, provoking a crisis that got Diefenbaker tossed out of office.

Harry Truman told reporters the Canadian prime minister was coming to see him, but avoided saying his name (Louis St. Laurent), "because I don't know how to say it." Kennedy got off to a bad start with Diefenbaker by calling him "Diefenbawker." Dwight Eisenhower, in a toast to the luckless Diefenbaker, welcomed the "Prime Minister of the great Republic of Canada" --and repeated it, just to make it clear he thought Canada really was a republic.

When Richard Nixon visited Ottawa in 1972, his advance men were rebuffed in an effort to remove Prime Minister Pierre Trudeau's tan furniture from his office and bring in more telegenic blue chairs. On the eve of his first visit to Ottawa in 1981, Reagan withdrew from the Senate a fisheries treaty of vital importance to Canada.

On and on the recital goes. Martin concedes that there was genuine friendship and cooperation between Franklin D. Roosevelt and Mackenzie King. He recounts a delightful meeting between Kennedy and Pearson at Hyannisport, which I was lucky enough to cover. But those were the exceptions.

His wild stories convey a serious point. The United States, through its presidents, has more often than not betrayed the most callous ignorance of the feelings, views, interests and sensibilities of the leaders of a country with which we are closely linked economically, politically and geographically.

We have been so unheeding that Sondra Gotlieb, wife of the current Canadian ambassador to Washington, once remarked to The New York Times, "For some reason, a glaze passes over people's faces when you say Canada. Maybe we should invade South Dakota or something."

We are the 800-pound gorilla in this hemisphere and, more often than not, we have acted it. We ought to bear that in mind when we decide that we have the wisdom to decide the future of some smaller country to whom the Lord has shown special favor by allowing it to live in the shadow of the United States.

The picture of Lyndon Johnson strangling Lester Pearson at Camp David is not one that clamors to be a model of what we like to call our "good neighbor" policy.