After textiles, steel and autos, are petrochemicals next? The United States and Europe are engaged in an increasingly bitter dispute over chemical exports, but this time the shoe is on the other foot. It's the Europeans, not the Americans, who say they're being hit with unfair and subsidized shipments. And they have aimed a series of actions at the heart of one of America's strongest export industries. Last year, the favorble U.S. trade balance in chemicals totaled $9.8 billion.

There is more to this than just another tiresome, technical trade quarrel. The petrochemical industry is one of the spectacular growth industries of the postwar era, but -- like steel, autos, textiles and apparel -- it is undergoing fundamental change. And, like those industries, economic stress has produced political pressures for governments to cushion its effects.

We are moving into an era of what British economist S.A.B. Page calls "managed trade." As a matter of practical politics, governments everywhere find themselves the custodians of key industries.

Government bureaucrats increasingly play the role of the robber barons in the 19th century: They try to prevent free markets from working. The robber barons organized trusts to keep up prices and safeguard investments. In the name of saving jobs, the bureaucrats subsidize weak firms -- impose import restrictions, but these steps also prop up prices and protect investments.

Between 1974 and 1979, according to Page, the proportion of the world's manufactured exports covered by import restrictions nearly doubled -- from about 13 percent to 21 percent.

But the effect goes further. Flourishing international commerce requires an atmosphere of certainty. Companies won't invest to serve export markets that may be shut down. So the mere possibility of restrictions may discourage trade and help governments work out global market-sharing arrangements.

In the United States, restrictions against textile and clothing imports go back to the 1960s, but the quotas are becoming progressively tighter. The steel industry apparently wants protection that could last well into the 1980s, and the auto industry -- led by the United Auto Workers, Ford Motor Co. and Chrysler Corp. -- seeks similar help. Petrochemicals may now be drifting into the same category, where trade flows are determined as much by political barganing as by economics.

Petrochemicals, of course, really mean the plastics, synthetic fibers, fertilizers, paints, drugs and other products that derive from oil and natural gas (coal could also be used, but, for now, is too expensive.) Synthetic fiber production has increased by a factor of more than 100 since 1950, synthetics now rival cotton as the most important fiber. Plastic output in the United States has risen ninefold since 1960.

A cultural snobbery attaches to this industry. There's a tendency to see polyesters and plastics as signs that civilization is moving backward. Petrochemicals have come to symbolize a destructive drive toward enviromental catastrophes and commerical monstrosites. Even less critical observers may conclude that the industry is doomed by high oil prices and will disappear in dinosaur-like fashion.

Not likely. In an excellent study of the industry's future, Christopher Flavin of Washington's Worldwatch Institute points out that petrochemicals account for only a small fraction (3 percent) of oil and natural gas consumption and that petrochemical products represent one of the most valuable uses of scarce petroleum. Although Flavin thinks that much plastic packaging is wasteful -- and will ultimately disappear as uneconomic -- he finds that many other uses of plastics and synthetics offer clear advantages over rival materials.

Plastic parts increasingly will make cars lighter and more fuel-efficient, he says, and fiberglass insulation will keep homes warmer. Plastic pipes require less energy to make than steel and last longer; even as packaging materials, plastic and paper may be at a standoff in terms of energy consumption. Flavin also cites a National Science Foundation study suggesting that a pure cotton shirt may have lifetime energy requirement higher than a blended polyester-cotton shirt, mainly because it required more ironing.

But Flavin and virtually everyone else agree that higher oil and natural gas prices have dramatically reduced the industry's growth prospects. Against annual increases of 8 percent to 10 percent in the late 1960s and early 1970s, analysts now talk in terms of 2 percent to 4 percent.

But when companies have been building plants on the basis of the higher growth rate and suddenly get the lower, the result is a lot of spare capacity.

That's precisely what's happened. In Europe, capacity for some petrochemicals is 25 percent more than needed. And the glut has been aggravated by the surge in American exports, which rose 37 percent last year. Between 1977 and 1979, for example, U.S. exports of nontextured polyester yarn increased from 7.7 percent of European consumption to 14.3 percent.

The explaniations for this vary. The U.S. industry and government officially say the European industry is substantially less efficient than the American, with many plants about half the size; the 15 percent depreciation of the dollar between 1977 and 1979 is said to have made U.S. products more attractive. And Europe's almost total dependence on oil as a chemical feedstock -- in contrast, many U.S. firms can shift to natural gas -- is seen as a huge liability.

By contrast, the Europeans argue that U.S. price controls on oil and natural gas subsidize U.S. petrochemicals to the tune of 15 percent to 20 percent. An analysis by one major U.S. oil company seems to support the European view.

Although European actions against American petrochemicals have so far been mild, tougher measures are rumored. The contradictions are messy. Governments do not believe they can let key industries suffer impersonal deaths from foreign trade, especially when that trade is deemed "unfair." Yet, neither do governments want to be saddled permanently with the burden of supporting inefficient industries. From such forces do political accommodations emerge.

In an ideal world, these deals would be temporary and allow a graceful phasing out of surplus plants. In the real world, there may be no such thing as graceful; the risk is that the deals will simply perpetuate surplus capacity while suffocating trade and sustaining high prices. p