SUPPOSETHE trade talks collapse next month. It looks increasingly probable. The consequences wouldn't be sudden or dramatic -- no immediate catastrophes. But there would be an increasing drag on economic growth throughout the world. It would be especially harmful to the United States, which is counting on a fast rise in exports to pull it rapidly through the recession that seems to be underway here and to give momentum to the recovery.

President Bush understands the importance of these talks and has been pressing other governments vigorously to respond. But he's distracted by the Persian Gulf. The European Community is similarly distracted by Eastern Europe and doesn't want to deal with the politics of its grossly expensive and disruptive system for protecting its farmers -- which will probably be the immediate cause of the trade talks' failure.

The purpose of these talks, known as the Uruguay Round, is to bring the rules of trade up to date. International trade has expanded enormously in recent years, reaching into new areas and involving products to which the old rules apply awkwardly or not at all. Practices that made little difference on a small scale now are major issues. Some products, such as textiles, have previously been left outside the trade rules. But if Third World countries can't sell their textiles in North America, they aren't likely to agree to observe American patent rights in their own markets.

If the talks fail, the world will have wasted a great opportunity to make international trade law fairer and more effective. Because the present system is inadequate, it will start to erode. Countries will increasingly rely on bilateral deals with each other. In the absence of established general rules, special interests will prevail -- always at the expense of consumers.

There are many trade quarrels here and in other capitals that have been held in abeyance pending the outcome of the Uruguay round. If these talks produce nothing, the lawyers will then go to work under national laws that, in this country and most others, have a strongly protectionist tilt to them. Since the process is adversarial, the rising friction will affect political relations among governments. It's all happened before, although not since 1945.

The Uruguay Round is the eighth cycle of world trade negotiations since World War II, and all of them until now have been, to one extent or another, successes. The result has been a steady force for greater commerce and rising prosperity. A failure now would threaten to turn economic history, and perhaps not only economic history, in other directions.