Today, the law is an avenging sword pointed straight at Union Carbide Co.

Tomorrow, it may be the company's shield.

Today, a posse of American lawyers is fanning out in Bhopal, signing up thousands of Indian plaintiffs for class action damage suits seeking $35 billion so far from Union Carbide.

Union Carbide has contributed $1 million to an emergency relief effort to aid the victims of the Dec. 3 poisonous gas leak in Bhopal and has promised to compensate the victims "fairly and equitably," although it has not yet spelled out its plans.

If the litigation of claims by asbestos workers against the Manville Corp. and other asbestos manufacturers is any guide, the litigation beginning now over the Bhopal disaster promises to stretch out for years. The defensive opportunities available to Union Carbide's lawyers appear endless, thanks to the complexity of the legal issues, including how the responsibility for safety at the plant was divided between Union Carbide, the majority owner of the Bhopal plant, and its Indian co-owners.

So the Indian victims who sue run the risk of waiting three, four, five years or more for a Union Carbide check. In return, the American lawyers in Bhopal are undoubtedly promising them that they will receive considerably more from a successful suit for punitive damages or a settlement of such a suit than they would have from Union Carbide's generosity alone. If the asbestos suits are a guide, the Indian victims also will turn over 35 percent of their compensation to the lawyers.

If this is ambulance chasing, so be it, said John Coale of Coale and Associates of Washington, D.C., one of the American lawyers in Bhopal. "If I come in from the airport and two days later have 7,000 clients, that's the greatest ambulance chase in history," he told The Washington Post.

The tactics of the ambulance chasing lawyers are almost enough to stir up a sympathetic reaction for Union Carbide. Unfortunately, they have a place as part of the adversarial system of checks and balances on which American society relies. We learn the hard way from mistakes, and among the teachers are the lawyers and the verdicts they win.

While courtroom pettifoggery has strung out the Manville asbestos litigation for years, it was the ambulance chasers who dug through the records, interrogated the witnesses and established the case that Manville should have acted sooner to protect asbestos workers from the threats of lung disease and cancer.

The problem with ambulance chasers is that they arrive after the accident. They aren't much help at sorting out the political calculus of risks and benefits that underlie the manufacture and use of countless industrial chemicals in modern society.

In the case of methyl isocyanate, the poison gas at Bhopal, the risks were frightening. MIC is a devil's brew. Its production begins with carbon monoxide, which is mixed with chlorine to produce deadly phosgene gas. That combines with methylamine to produce the methyl isocyanate.

But MIC is used to make Sevin Carbaryl, one of the powerful pesticides that helped create the Green Revolution and enabled India to feed itself. India could have done without Sevin, but it can't kill crop-destroying insects with dishwasher detergent. If it shunned Sevin, it would have had to find some other lethal pesticide or bear a burden of hunger.

Who is responsible for these trade-offs? The Bhopal tragedy already has triggered new denunciations of American multinationals for their conduct in the Third World. "This is the Americans' way of doing business -- the great Union Carbide and the poor Indian," said attorney Melvin Belli, pausing in his recruiting campaign for Indian plaintiffs.

That reasoning overlooks the responsibility Indian officials appear to bear for what happened at Bhopal. Union Carbide says it was obliged to hire local management; although it built the plant on the outskirts of Bhopal, it had no direct control over the 100,000 people who camped next to the plant, setting up the shantytowns that were enveloped by the poison cloud.

Ultimately, however, these facts don't wash away Union Carbide's responsibility, whatever its legal liability turns out to be. Union Carbide officials say there had not been a major safety audit of the Bhopal plant in more than two years, adding that responsibility for detailed design of the facilities at Bhopal rested with the Indians. That is the choice made by the Indian government in its effort to advance its technological expertise. It is true that India wanted pesticides and would have acquired the manufacturing capability from someone else, if not Union Carbide.

But no one has more expertise than Union Carbide possesses on the risks of manufacturing, handling and using methyl isocyanate. That is where the buck stops.