It's been 40 years since the surgeon general issued the first report warning that cigarettes cause cancer. Since then, the public has grown acutely aware that smoking is lethal. But though the public education campaign has been a great success in providing information, it's been a failure in one conspicuous way: 46 million American adults still smoke.

How come? Because it's so hard to quit. Nicotine is so powerfully addictive that lots of people find it impossible to give up--even with lung cancer, emphysema and heart disease staring them in the face. Despite an array of products and strategies designed to help people conquer the habit, cigarettes remain a major killer in this country.

If we want to know how to reduce the health toll from tobacco use, we might want to look at Sweden, where smoking among men has dropped sharply in recent years. How come? Brad Rodu, a professor of pathology at the University of Alabama at Birmingham, says one big reason is that a lot of Swedish smokers have switched to smokeless tobacco.

That may sound like a pointless exercise, substituting one deadly addiction for another. In fact, snuff and other unsmoked forms of tobacco are not nearly as risky as the kind you ignite and inhale.

A 2002 report by Britain's Royal College of Physicians noted that "the consumption of non-combustible tobacco is of the order of 10 to 1,000 times less hazardous than smoking." Smokeless tobacco is known to cause oral cancer. But Rodu estimates that if everyone now smoking made the change, the annual number of tobacco-related deaths in the United States would plunge from 440,000 to 6,000.

U.S. Surgeon General Richard Carmona, who says he would like to ban all tobacco products, insists that "there is no scientific evidence that smokeless tobacco products are both safe and effective aids to quitting smoking." Anti-smoking groups portray smokeless tobacco as an intolerable danger. But a growing pile of evidence suggests snuff could be a valuable tool to help smokers help themselves.

It's true that they'd do well to swear off the weed in any form. But when virtue fails, as it often does, we have to look for ways to make vice less dangerous. That's the rationale for giving teens access to condoms and other types of birth control, even if we strongly prefer that they abstain from sex. It's also the idea behind needle-exchange programs, which recognize that one thing worse than injecting heroin is injecting it with an AIDS-infected syringe.

Smokeless tobacco offers hope to hard-core smokers because it lets them fill their nicotine needs without sucking toxic fumes into their lungs. Addicts would be better off getting their daily dose without lighting up.

The rest of us would gain as well, since this indulgence lacks a notable byproduct of cigarettes: secondhand smoke. (With some forms, the user doesn't even have to spit.) And nobody ever burned down his house by falling asleep while dipping snuff.

You may wonder why any smoker wouldn't use nicotine gum or patches instead. Answer: because they're more expensive and less potent, relieving smokers of their cash but not their cravings. While nicotine maintenance works for some people, it doesn't work for others, and they shouldn't be deprived of additional options.

Critics dismiss Rodu as a hired gun for the smokeless tobacco industry, which in recent years has donated money to support his research and would like to market its product as a safer alternative to smoking. But he says his studies between 1993 and 1999 were done without any industry financing. The funds the industry has given since then have been unrestricted grants to the University of Alabama at Birmingham, and it has no control over the research.

Attacking his funding seems to be easier than refuting his evidence. If the tobacco industry donates money to scientists who say the sky is blue, that doesn't make it green. Instead of rejecting the scientific data that has been produced on the subject, the surgeon general should be demanding government funding for additional research.

Based on the evidence so far, though, smokeless tobacco is far less dangerous than cigarettes, and the industry should be free to publicize that fact. The ideal solution, of course, is for everyone who smokes to quit tobacco once and for all. But when people can't or won't do what's best for them, we shouldn't discourage them from doing what's second best.