THE NINE NATIONS of North America is in a great tradition: first John Gunther, then Neal Pierce, now Joel Garreau. All have tried to get a broad understanding of the United States (and a little bit more for Garreau) from a detailed touring-and-talking series of excursions to the grass roots. Each had an exhausting schedule, and it isn't a program of Holiday Inn nights that most researcher-writers would want to undertake carelessly.

This newest volume, written by an editor of this newspaper, is an outgrowth of an article written two years ago and now very much expanded. The special contribution of Garreau is that his review of what Jimmy Durante used to call "the conditions what prevail" expands the earlier state-oriented studies into Canada, Mexico, and the Caribbean. Not that readers in these added areas may always agree with the themes of Garreau's treatment of their home ball parks. Indeed, my guess is that some outraged screams may be heard across the borders, from north, from south, and across the water.

But Garreau's efforts have the wonderful value of being interesting, even exciting, agreeable or not. He writes what might be called "neo-geopolitical picture building," and he writes well. He tries to reexamine contemporary life in his "nine nations" and to make a few guesses about the future, and the nature of these gueses is intimated in the titling and bounding of the nine areas he considers.

The core of North America, "the Foundry," includes the industrial East and Middle West, plus southern Ontario. This area, at least in Garreau's view, is the only one of his nine which is actually in not very good shape, with its real glory days past and with an uncertain future. "The problem with the Foundry is that it is failing. Its cities are old and creaking, as is much of its industry . . . The Foundry is the only one of the Nine Nations that can be said to be on the decline."

Certainly the last American census would bear out much of what Garreau says. It is from this area that most of the "losers" come in terms of states losing House of Representative seats in the next (1982) Congress. The flow of House membership, reflecting comparative flow of population, is from the East and Midwest (and especially from the cities in these states) to the Sun Belt. I doubt these same cautions would apply to southern Ontario, and the problems of Toronto seem small beside those of New York and Detroit and Cleveland, but that is an issue which Canadians can dispute on their own with author Garreau.

But the other "nations" aren't in bad shape. On the contrary, "The other eight are, at worst, economically stable (for example, Quebec and New England), in the sense that a plausible balance between quality of life and modest growth rate make for stability. And others are generating wealth and growth so fast that their biggest problem is controlling the boom." The "stable" areas cited are Quebec province, but just the province, not including northern New Brunswick and other parts of French Canada outside Quebec proper, and New England, to which the author adds Maritime Canada.

The "boom" parts include: "Dixie," "an emerging nation," entirely within the United States but including a bit more than the traditional Confederacy and dropping off southern Florida; "Ecotopia," or the Pacific rim right up to southern Alaska; and "MexAmerica," headquartered in Los Angeles, running over to Houston and down into a good deal of northern Mexico.

Moving his "boom" regions eastward, Garreau includes the Antilles, the northern coast of South America, and southern Florida in a grouping called simply "the Islands." A descriptive logo consisting of a palm tree over two dollar signs might indicate the real problems and extremes of wealth and poverty in this region. Finally, the central areas of North America are titled simply "the Empty Quarter" (west and "the Breadbasket" (east. Both merge large pieces of Canada and the United States and their names indicate their present functions -- one waiting for new uses, most likely in energy fields, and the other the food producer.

In all these "nine nations" Garreau has travelled and talked, and now written. The material is interesting, good, and often controversial. To this reviewer, as one example, the idea of the whole continent as a study area is fascinating, but to project this onward towards anything approaching political or economic coordination or unity makes a very large jump. Indeed, it may not be a jump Garreau intends, and it may be carrying the message too far even to suggest the possibility.

But if larger futures are to be drawn from this volume, it must be to that goal of coordination rather than towards disunity. Certainly a degree of cooperation is more likely than the creation of new competing areas to follow the identified "nine nations" described in this study. Even though viewing the future with any certainty is a dubious effort at best, the stimulation of this volume is such that the mind naturally projects current data forward.

The Nine Nations of North America is best read as a wonderfully intriguing story of the world immediately around us -- here and now, viewed through a rather different kind of glass, perhaps like the old stereopticon slides, with a different focus and dimension. It is a grand book.