We are now witnessing the end of one of the great hibernations of modern history.

Think what you will of President Carter's recognition of the People's Republic of China -- a courageous act, a betrayal of Taiwan or a cheap grab for popularity -- its significance pales beside China's own decision to end 30 years of economic isolation.

At one level, materialism has triumphed over ideology. Since World War II, materialism has become a global religion, propelled forward by new commercial and financial institutions -- multinational banks and companies -- and nurtured by a benign intellectual climate. Growth was good, and former colonies were encouraged to emulate the West's industrial development.

Superior and suspicious, China stood aloof from this. A statistic tells the story. In 1978, a country with nearly a fourth of the world's population -- one billion, give or take a hundred million -- will generate a puny 1 per cent of the world's trade: $20 billion out of $2 trillion.

The alienation accurately reflects a century in which China was repeatedly raped and betrayed by outsiders, climaxing with the Sino-Soviet rift of the late 1950s. By that time, China had allowed itself to grow dangerously dependent on the Soviet Union. Born of necessity, economic isolationism acquired powerful defenders including Mao Tse-tung and his ideological heirs, the so-called Gang of Four.

They did not oppose economic growth so much as they insisted on the supremacy of ideology -- whatever it happened to be. Economic managers, including the scientists and technicians demanded by a modern economy, had to be controlled. Trade was to be strictly limited. Debt was virtually taboo.

In practice, this produced a schizophrenic China. On the one one hand, it strove strenuously for economic growth. In the period from 1952 to 1974, it reinvested 20 per cent to 25 per cent of its output (nearly twice as much as the United States), which meant that new steel was going for more railroads and factories, not consumer goods. Growth averaged 6 per cent, which compares favorably with most developing nations.

But the technicians and ideologues clashed repeatedly, and the economy suffered from their combat. In the Cultural Revolution, officially dated between 1966 and 1969, intellectuals, technicians and their political allies were dismissed from power, sometimes brutalized and, more often, humiliated. The struggle for Mao's power disrupted the economy for two years. In 1976, it did not grow at all.

It is tempting to see the triumph of the pragmatists as a morality tale in which the good guys -- sympathizers with our way of life -- have won. Even more tantalizing is the prospect of a commercial boom that will revitalize world trade. But the story is more complicated.

Even with its growth, China's economy remains primitive by Western standards. Probably three-fourths of the population is still rural and works the land. The rail network has doubled since 1952, but is only one-sixth the size of the United States'. In a country where the bicycle dominates individual transportation, China produces half as many bicycles annually as America produces cars: the cost of a bike is about a months' salary.

More important, China is now exhausting its potential for rapid internal growth. In the workers' society, the worker has had to pay for almost all of China"s progress. Between 1957 and 1977, real wages for manufacturing workers didn't rise at all, according to Nicholas R. Lardy, a Yale University economist. Consequently, Lardy believes, discouraged workers have hampered growth. Only the incentive of higher wages -- which means more consumption or inflation -- can restimulate productivity, he says.

At the same time, the needs of a growing economy overwhelm China's productive capacity. In 1977, steel alone constituted more than a fifth of China's imports, and fertilizers -- required to keep food output rising along with the 2 per cent annual population growth -- another 5 per cent.

Given these pressures, China's needs for imported technology and plants, shortcuts to growth, are vast. Not surprisingly, the smell of bonanza is in the air. Japan's Nippon Steel Co. has sold a $2 billion steel plant; Bethlehem Steel Corp. is negotiating for iron ore mining facilities worth several hundred million dollars. The Boeing Co. recently sold three 747-Sps, and U.S. hotel chains will design and build perhaps $1 billion worth of hotels.

You can imagine executives from Frankfurt to Tokyo salivating at the China connection, but the bonanza, if it comes, will develop slowly. A country can import only by exporting or borrowing and, put simply, China does not yet have much to sell.

Its biggest exports -- inexpensive textiles and clothing -- also pose political problems. They threaten already-beleagured garment workers and firms in the West, and, therefore, may be restricted. Less menancing are China's hopes to build foreign exchange earnings by exporting oil and promoting tourism. Those 747s should pay for themselves, as should the firstclass hotels.

But none of this will come quickly. No one, for example, knows how much oil China has. Estimates range from about 30 billion barrels of reserves (about equal to the United States) to 150 billion barrels (approaching Saudi Arabia). Even if the high estimates prove correct, oil fields take five to ten years to develop.

For the moment, China will be able to borrow -- in part, because it rarely did so in the past. At the end of 1977, its debt stood at $1.3 billion. It's easy to see another $4 billion to $8 billion piled on top of that. But even that is small against China's needs.

So the change will come slowly, but if it proceeds uninterrupted its implications are staggering. Should China follow the development pattern of its Asian neighbors including Japan and Korea, the world economy will have undergone a facelift of unimaginable proportions. And what that will do to world politics, no one knows.