Just when you think the politicians have wasted their time and our money on every harebrained scheme imaginable, Montgomery County lawmakers prove that they haven’t yet plumbed their potential for legislative mischief.

On July 1, for the second time in four years, the County Council voted to ban smoking in restaurants and bars. The new law circumvents procedural problems cited by the Maryland Court of Appeals when it threw out the original ban this past May. But some things in the county never change — including the urge to engage in social engineering with too little concern for personal liberty or private property.

While the lawyers plan their next round of challenges, smokers and nonsmokers debate which group’s rights should trump. Actually, the rights that matter are neither the rights of smokers nor those of nonsmokers. To put it bluntly, the owner of the property should be able to determine — for good reasons, bad reasons or no reason at all — whether to admit smokers, nonsmokers, neither or both. Customers or employees who object may leave.

That’s the controlling principle: Private property does not belong to the public.

According to supporters of the ban, business owners have no cause for concern. The evidence suggests, they claim, that patronage of restaurants goes up after smoking is banned.

That assertion is dubious at best. Many restaurants don’t enforce smoking bans, or switch to exempt outdoor cafes, so before-and-after comparisons are suspect.

More important, each business is unique. Who can best determine the effect of a smoking ban, the owner of a restaurant or a member of the County Council? Naturally, the owner bears the consequences of his decision.

Not so the council member. And even if aggregate restaurant business were to increase, may the council simply ignore the rights of those businesses that are harmed? Or those businesses that have already invested heavily in special ventilation equipment?

A second argument for smoking bans goes like this: Rules against smoking are analogous to regulations that protect against impure foods and unsafe premises.

Surely property rights do not absolve restaurateurs of health and safety infractions. What, then, is different about the regulation of smoking? The answer is straightforward: Restaurant patrons have no advance warning of contaminated food or, say, asbestos in the air. That’s not the case with second-hand smoke. Customers and employees are aware of the risk up front and can easily avoid the risk by going elsewhere.

Many restaurants in Montgomery County voluntarily choose a smoke-free environment; all others are required by state law to offer nonsmoking areas. Mostly, customers rely on common courtesy and mutual respect in adjusting to varied surroundings.

But nosy, intrusive government has exacerbated the problem. As a result, venom has replaced respect, and obstinacy has replaced courtesy. It is government, not secondhand smoke, that has poisoned the atmosphere.