Japan is a nation of beef lovers. Each year its citizens eat roughly a million metric tons of the stuff. So when Japanese scientists diagnosed a cow with bovine spongiform encephalopathy (BSE) in September 2001, it was nothing less than a national crisis. Fortunately, the Japanese could count on that other great beef-eating nation to satisfy their appetite for red meat--any restaurant or food supplier that used American beef made sure to advertise the fact. Yoshinoya D&C Co., a restaurant chain that specializes in gyudon--bowls of stewed beef over rice--was sitting pretty: it imports 99 percent of its beef from the United States.

Then, a few weeks ago, an American cow tested positive for BSE, triggering 48 countries, led by Japan, to ban the sale of American beef. About 36,000 metric tons of prime U.S. beef was left marooned on docks or aboard ships. Fast-food outlets throughout Asia were advertising Australian or New Zealand beef, while restaurants like Yoshinoya, which had bet almost exclusively on the safeguards of the American beef industry, was left high and dry. Unless Japan lifts its ban, which is unlikely, Yoshinoya's 980 outlets will run out of beef entirely in February. The company is adding more nonbeef items to its menu, including chicken and salmon over rice. "This is the worst of the worst cases," says company president Shuji Abe.

How could the land of the Double Whopper fail to foresee the predictable danger of BSE? Just two years ago American food officials watched Europe go through its own BSE hell, when it was forced to destroy more than 7 million head of cattle. Since then, critics have warned repeatedly that the affliction would show up in the United States. Indeed, many Americans were shocked to learn that a cow too sick to walk had been slaughtered and shipped off to supermarkets--all perfectly legal and under the watchful eye of the U.S. Department of Agriculture (USDA). By the time a voluntary recall was announced, two days before Christmas, it was likely that at least some of the questionable beef had already gone where no USDA inspector could retrieve it.

The episode cast an unflattering light on a food-safety system patched together out of a dozen overlapping jurisdictions, operating by laws in some cases nearly a century old. It's a system that seems dangerously unprepared to cope with the kinds of threats likely to arise in the 21st century, even those as predictable as BSE.

What's maddening about mad-cow disease, of course, is that the risks are so difficult to quantify. One could make a pretty good argument that they are negligible--many advisers to the USDA did just that. Salmonella is "much more of a risk" than BSE, according to Dr. Lester Crawford, deputy commissioner of the U.S. Food and Drug Administration. Even seemingly harmless vegetables can be just as dangerous. Hepatitis A, which sickened more than 500 people at a Pennsylvania restaurant in October, can be transmitted by bacteria on contaminated veggies. A report by the U.S. Centers for Disease Control counted 2,751 outbreaks of foodborne disease between 1993 and 1997--and by far the most dangerous category of food, with 12,537 cases, was fruits and vegetables.

By contrast, the number of Americans with variant Creutzfeldt-Jakob disease (vCJD), the brain disorder linked to BSE, is essentially zero, and few scientists expect that finding a single mad cow will cause that number to go up much, if at all. In Britain, where hundreds of thousands of cows were infected with BSE back in the 1980s, the number of new human cases has leveled off at fewer than 20 a year, not the tens of thousands that some scientists once feared. (Researchers caution that so little is known about the disease they can't be sure the worst is over.) Still, the insidious nature of vCJD, which can incubate for years before erupting into dementia, paralysis and death, looms larger in many consumers' minds than the infinitesimal chance of catching it.

The American beef industry is facing a long road to recovering the world's trust. McDonald's issued a press release about its longstanding policy against using "downer" cattle, like the one implicated in last month's recall. One of the biggest steps U.S. Secretary of Agriculture Ann Veneman took last week was to ban the sale of meat from these animals. They accounted for between 150,000 and 200,000 of the 35 million cattle sent to slaughter last year, of which only 20,000 were tested for BSE.

Veneman also toughened up regulations on what is known as "advanced meat recovery"--machinery that strips every scrap of protein off the bones of a carcass, sometimes inadvertently harvesting scraps of nerve tissue along with the muscle. But critics like Marion Nestle, a leading nutritionist, say what's really needed is an overhaul of the food-inspection system. As she points out in her book "Safe Food," American food is regulated by 12 different agencies, from Customs and Border Protection to the Environmental Protection Agency; pizza falls under either the USDA or the FDA, depending on the topping.

What the government has failed to do is institute tough reforms in the way cattle are fed. Most scientists believe BSE infects cows when they are fed the ground-up carcasses of animals--including other cows. Both the United States and Canada (where the infected American cow is thought to have originated) banned this practice in 1997, but consumer groups say the ban is full of loopholes and poorly enforced in any event. For one thing, dead cattle can still be fed to other animals. Together with all the parts left over from slaughtering, they are often "rendered"--boiled down and dried to a powder--and made into chicken feed. But what happens at the henhouse? "Whatever the chickens don't eat becomes waste material that is combined with dead chickens [and] fecal material and rendered to feed back to cattle," says Caroline Smith DeWaal, director of food safety at the Center for Science in the Public Interest.

What's needed, say critics, is a total ban on rendered feed for all animals, and testing of every cow that enters the food supply. Japan already does that, and Europe tests every animal older than 30 months (the age at which the incidence of BSE starts to climb), says Dr. Stephen De Armond, a neuropathologist at the University of California, San Francisco, and an authority on BSE. To test every head of cattle in America "wouldn't raise the price of beef by more than 10 to 20 cents a pound," De Armond says. "And it would make me feel a lot better." No doubt the same is true for consumers around the world, so enacting such safeguards might ultimately make the American beef industry feel a whole lot better, too.