The Polk County supervisors are considering a rule that would move cold medicines containing pseudoephedrine, a key ingredient in the manufacture of methamphetamine, behind the counter. The goal is to make the drugs harder to buy or shoplift.

This measure would create a minor hassle for consumers and a larger one for retailers, but that’s not the issue. We should be willing to play our part in fighting meth. The real question is, how effective would it be?

To skirt the regulation, drugmakers could purchase pseudoephedrine on the Internet, in any number of our closely spaced towns or by visiting stores in Greater Des Moines one by one. A group working together could make a series of individual trips into each store. And, of course, some meth makers will be more than willing to wait until after closing time and then break in.

Will we assign people to monitor and cross-check the store registries? Will we launch an investigation every time we isolate a suspicious name? Would doing so be an efficient use of law officers’ time?

And if all this actually reduced the quantity of homemade meth, isn’t that likely to simply open the market to dealers from elsewhere? The U.S. Drug Enforcement Administration says organized crime groups operating in Mexico tap wholesale sources of ephedrine on the international market to produce and distribute vast quantities of meth.

Iowa already has limits on the sale of cold medicine with pseudoephedrine as the only active ingredient, and the entire country has the Comprehensive Methamphetamine Control Act of 1996.

When the federal government enacted that law, it made reference to several actions that should arouse retailers’ suspicion. For example, they’re supposed to watch out for customers who ask for more than the transaction limit in effect, buy the limit several times within a few days; buy only the largest size available or buy other products from a long list of meth-making ingredients.

Farmers and co-ops have tried to make it harder to steal ammonia from fertilizer tanks, too.

And yet, meth continues to be a major problem in Iowa, so we know that we haven’t hit upon the solution.

That’s why we find ourselves, as always when we face a tough problem, considering another layer of government control.

We should be willing to go to great lengths to protect our children and ourselves and to help our law enforcement officials fight a difficult and dangerous battle.

But we shouldn’t waste time and hope on efforts that are unwieldy and probably ineffective.