BACK IN 1952, I was visiting the Yucatan Peninsula and was struck by the number and the fervor of penitents winding their way on their knees toward the poor and beautiful churches of the region.

I asked what these descendants of the ancient Maya, who during 2,000 years had been praying to the gods for rain and harvests, might now be asking for. The answer was simple: "They are praying that the war in Korea will not end. If it does, they will not sell the hemp fiber, and everyone shall be poor again, poorer than before the war boom."

I have not forgotten the brutal irrationality of that situation. On Thursday, 22 heads of state and government from seven developed and 15 developing nations will meet at the resort island of Cancun on the Caribbean, not far from the villages where those campesinos, 30 years ago, were offering prayers for the continuation of the war in Asia that pushed up demand for their exports.

Today's economic crises was perfectly contained, as in a miniature, in the drama of those Mayan farmers held hostage to the balance of payments.

Nobody seemed to care much then. It is time to care now: The world economic crisis has engulfed us all, rich and poor nations. Cancun is an urgent attempt to deal at the highest level with the problems shared by the world economy.

The widespread notion held by Western public opinion that, in matters of development and cooperation, it's "we" versus "them," or that "they're out to get our money," should be dispelled at Cancun. Massive transfers of wealth from North to South are not the issue. Mutually beneficial collaboration to create new wealth is the issue.

The conference convenes as both an epitaph to a vanished world and the tentative response to a new economic, political and cultural world we dare not name yet.

The vanished world is that of seemingly unlimited economic expansion, secure markets and cheap sources of energy and raw materials. Since 1945, the world community of nations has mushroomed threefold from the 50 original signatories of the United Nations charter at San Francisco. Decolonization has created challenges and opportunities unthought of at the 1945 Bretton Woods conference that created the postwar economic system. Hundreds of millions of new people are striving to enter the world economy and to define the relationships between their cultural identity and their nationhood (often at odds with each other) as well as their place in the international community.

How to modernize without westernizing? This is a forceful dilemma, since it proposes the need to achieve health, wealth and efficiency without sacrificing deep ethical and cultural roots. It is a dilemma that soon meets yet another: How to reconcile the growing expectations of these developing countries, the growing consciousness of their own interests and identity, with the traditional power and high living standards of the developed world.

By the early '70s it could be stated that the growing awareness of cultural and political diversity in the Thirld World was not divorced from the emergence of economically literate cadres and addition of technology and its capacity to elevate standards of living for three-fourths of the worlds's population.

Furthermore, the developing nations entered an expanded credit market at the same time that U.S. deficit dollars and OPEC liquidities spiraled beyond anyone's purely national control. These were the "engines of inflation," as Ambassador Andrew Young called them in a brilliant article of March 1980, and if the developed countries were quick to respond to the perceived threat of OPEC, demanding netotiations on energy, they were not as agile in perceiving that petrodollars were but a subordinate factor in a wholesale inflationary spiral that was international, huge and uncontrollable without concerted actions: It was a question of $700 billion thrashing around the world, linked to no productive sequence and serving only speculation based on quick returns. Was not this sufficient reason, argued Young, for a "reconvening" of the Bretton Woods conference in order to create a developmental facility that would permenently remove from the speculative markets at least $200 billion of the "hot dollars?"

Calles to action such as Young's have not been lacking since the early '70s. Presidents Houari Boumedienne of Algeria and Luis Echeverria of Mexico urged movement toward a "new world economic order." The Mexican-sponsored charter of economic rights and duties of states was approved by the U.N. General Assembly in 1974 and President Carlos Andres Perez of Venezuela, in a demanding and courageous letter, spelled out to President Ford in 1975 the dangers of a prolonged imbalance between developed and developing nations.

The Paris conference convened in 1975 by President Valery Giscard d'Estaing came to a depressed halt in 1977. All the dangers inherent to negotiations between haves and have-nots were flagrantly present: blame-casting, divisive rhetoric, lack of true political will. Perhaps these were, after all, the virtues of the Paris meeting. But the international crisis did not wait for the experts assembled at the Hotel Majestic: The debt-fueled growth of the Third World came viciously to a full circle as it beccame debt-constrained growth, and the pattern of dependency was stretched to the extremes of the tolerable and even transcended itself as the crisis of the developing world met the crisis of the developed world.

For the rich, the inflation plus unemployment, low or zero growth, declining standards of living, shrinking social services and (as demonstrated by Britain but perhaps not only for Britain this summer) what Lester Thurow calls a "cancellation . . . of social tolerance" from low and middle-income groups long attuned to measures of social progress in lieu of methods of social confrontation.

For the poor, it meant extreme dependence on exports: non-oil-producing countries of the third World must today pay for 50 percent of their imports with 100 percent of their exports. This, accompanied by lack of public capital for infrastructure and market facilities, without which private capital is not forthcoming, means that we have all become Mayan farmers.

The major irrationality of developing societies is that they cannot buy what only the developed countries produce and are thus condemned to potential -- never effective -- consumers. Not only is the planning capacity of these countries practically annulled; they are the dark mirrors of an interdependence that condemns them to stagnation because they cannot buy what they need to plan their growth.

But now this stagnation is shared with the developed world, and this is where Cancun comes in. For this week's summit meeting can only be a result of an awareness of our glaring interdependence. The era of unlimited expansion is over; so is the time when the developing world needed the developed world more than the reverse. The time for concerted action is here and President Jose Lopez Portillo of Mexico and Chancellor Bruno Kreisky of Austria, the cohosts at Cancun, have seized the opportunity to implement the conclusions of the 1980 Brandt Commission report in a meeting which hopes to overcome divisions, searches for guilt and ideological phantasms in the name of a very simple and very vital option: cooperation instead of controntation.

Energy is a problem of international cooperation: The oil-importing developing countries, points out the Mexican economist Horacio Flores de la Pena, have 15 percent of potential world reserves but only 2 percent of proven reserves. It is in the interest of Japan as well as Jamaica that there be ready financing of new sources of energy in the oil importing countries. Mexico, for example, is currently and unilaterally helping Cuba to explore her offshore oil possibilities. We believe that the day when Cuba is self-sufficient in energy, her true independence shall begin. Massive transfers? No: cooperation, mutual benefits, as in yet another example provided by the 1980 San Jose Agreement whereby Mexico and Venezuela, independently of political likes or dislikes, provide 200,000 barrels of oil daily on concessionary terms, to all the importing nations of Central America and the Caribbean.

Trade is a problem of international cooperation: The developing countries depend on the rekindled growth of the developed countries if they are to export raw materials and even energy; but they must depend on their own industrial growth if they are to import capital goods and technology from the developed countries. Economic health, as well as true international division of labor, are clearly two-way avenues. Cancun should make it clear to Western and Japanese public opinion that it is in everyone's interest that the developing world should obtain greater access for its manufactured goods in the developed markets if they are to continue importing capital goods and the technology incorporated into them from the advanced nations.

And certainly, the problem of hunger -- the direst, most urgent problem of development -- is a matter of international cooperation. The foreign minister of West Germany, Hans-Dietrich Genscher, warned at the United Nations recently that in the next 20 years, the world's population will jump from 4.5 billion to 6.5 billion. How shall 2 billion more people be fed, housed, educated, offered jobs and sources of energy? The answer vastly depends on the possibility of raising food production in the developing world by 4 percent annually. This would cost some $200 billion in 15 years. The developing countries are capable of putting up half that sum. The other half should come from international aid, because self-interest indicates that without a breakthrough in agricultural production, the dual societies of the Third World shall never become the growing, viable partners of Japan and the West. The Lome Agreement between Western Europe and 61 developing countries realizes this and again sets an example of complete cooperation.

We are speaking of three fundamental areas of economic reactivation d ependent on common interests and cooperation. If a breakthrough and then a follow-through on these matters can be achieved at Cancun, the meeting must be deemed a success. For none of these issues is even approachable without concerted action between the countries that have technology, idle productivity and high unemployment: the countries that have high potential demand and limited purchasing power; and the countries that have financial resources derived from oil exports. If these three groups are capable of cooperating rationally, we will be on the way to a reawakening of the world economy where greater demands from a growing Third World economy will be a factor in creating greater use of labor and equipment in the developed world, thus reducing costs and prices but, also, reducing the gulf between potential and real demand in the developing world. These are the ways in which we can all create new wealth, rather than squandering or giving away scarce resources. Recent messages from France, Germany, Sweden and the British Commonwealth indicate that there is a forceful trend now in this sense.

These, and not the so called "massive transfers of wealth from North to South," are the real problems to be considered at Cancun. I mean, the real economic problems, for behind them lie the variety of historical, cultural, political and even psychological problems that can be either a boon or an obstacle to understanding. The very diversity of interlocutors indicates that there is a variety of policies that today are left dormant because of lack of imagination or ideological adherence to programs that have been tried and failed. We must learn to deal with variety, and Secretary of State Alexander Haig was right when he declared, at this year's General Assembly session, that "our goal is not to impose either our economic values or our judgments on anyone. In the final analysis, each country's path to development will be shaped by its own history, philosophy and interests."

Two hundred years ago, the United States freed itself from colonialism at Yorktown. It did so with a hefty assist from an extracontinental power, the French Bourbon monarchy. The United States did not then become a satellite of Louis XVI or import French royalism to the new world. As an independent, revolutionary, developing and nonaligned nation, the United States found its own economic path in private initiative constantly tempered by social reform.

Perhaps the United States should come with the Spirit of Yorktown to meet the Spirit of Cancun, where leaders as varied as a French Socialist, a Japanese liberal or a Mexican nationalist can readily demonstrte that economic progress can be achieved under political and economic circumstances other than what Secretary Haig calls "reliance on . . . individual economic performance." France has relied on state intervention from Colbert to Mitterrand for its basic stimulus, and Japan and Mexico on the precedence of a strong national state over modern social classes created by the state thanks to the "magic" of public investment.

All these forms of native genius should not be denied at Cancun by ideological dogma. The United States traditionally has had trouble adapting to the world at the beginning of each new administration. (A possible exception was the supremely agile Nixon presidency.) But as a rule, the political promises of the fall election harden the international postures of the winter inauguration: Was there ever a speech more bellicose than John F. Kennedy's at his inauguration? Then the slow process of learning that the internal politics of the United States do not shape the reality of the world begins, along with the spring lesson that not only is the United States not alone in the world, but that it is not alone with the Soviet Union. The United States then begins blindly butting into shapes it starts faintly recognizing as "Mexico" or "France" or "Nigeria" or "India."

All these shapes will be three-dimensional presences at Cancun. Not the least of the possible virtues of the meeting is that it might quicken the pace of the Reagan administration's adaptation to an awareness of the real world.

Cancun is taking place because the crises has caught up with the negotiations. The South has now become a part of the North. It is good to know that, in Secretary Haig's words, the United States will participate in a "constructive and cooperative spirit" at a meeting that offers a "novel opportunity to gain fresh understanding." It is good that public opinion in the United States and throughout the West becomes sensitized to a set of problems whose solution, in the words of the French foreign minister, Claude Cheysson, does not imply charity or massive transfers, but a prerequisite for world development and world peace.

A shall be at Cancun this week and study faces, attitudes, words, psychologies. Western Europe and Japan know that their meager natural resources make cooperation with the emerging nations a matter of life and death. They shall be in the engine of the North-South dialogue. It would be a sorry sight if the United States were to remain on the platform of the last car, waving goodbye to the sunset.

For if Cancun is not a success, the problems shall not evaporate. They shall come back, violently, in the streets of Detroit and Liverpool, in the slums of Karachi and Rio de Janeiro and in the fields of Yucatan where the children of the campesinos I saw praying for a bloody war from which to wrench a meager livelihood 20 years ago are still hoping, still waiting, not far from Cancun.