PITY THOSE poor presidential candidates. No sooner do they make a decent showing in the horse race than they are exposed to tiresome policy questions that they would much rather avoid. The latest example is Elizabeth Dole, who finished a surprisingly strong third in the Republican straw poll in Iowa last weekend. Suddenly she is being grilled on abortion, evolution and homosexual Boy Scouts. Let us throw another issue on the barbecue.

Speaking in Iowa, Mrs. Dole denounced the administration's drug policy. There is always a lot to say, pro and con, about any administration's drug policy. Mrs. Dole may not have made the wisest choices. She began by accusing the president of failing to use the bully pulpit to warn children off drugs. In fact he has mounted an ambitious and by some accounts effective advertising campaign to do just that. She went on to accuse Mr. Clinton of cutting the budget for drug interdiction. Actually, the 1999 interdiction budget is up 11.8 percent from the previous year. Finally, Mrs. Dole implied that Mr. Clinton was especially indifferent to the flow of drugs through Mexico. If elected, the candidate went on, she would demand that the Mexicans stanch this flow; if that failed, she would use her powers as president "to shut that spigot off."

Perhaps Mr. Clinton heard her. More or less as she was speaking, the FBI and U.S. Drug Enforcement Administration were closing in on a Mexican-based drug ring that distributed marijuana and cocaine to American consumers. The bust involved some 100 arrests. Among other things, it is said to confirm that the recently stepped-up information-sharing between Mexican and American anti-drug officials is a project worth pursuing.

Candidates almost always oversimplify. It's the nature of campaign communication. But Mrs. Dole, in addition to calling for forcefulness, needs to show she understands the complexities of the battle against drugs abroad. America seeks to eradicate crops, break cartels, seize shipments, but at the same time cannot appear to be trampling on the sovereignty of allies whose support it needs in the very drug operations themselves. Recent talk that the Clinton administration might dramatically increase its anti-drug effort in Colombia produced a backlash in the region. Colombia's president, Andres Pastrana, had to defend himself against nationalist critics who complain that the war on drugs has supplanted the threat of communism as America's excuse to meddle with its southern neighbors.

The day before the Iowa straw poll, a gunman on a motor bike murdered Jaime Garzon, a celebrated Colombian comedian who had tried to mediate in his country's drug mayhem. Two days later, more gunmen on motorbikes attacked Mexico's top anti-drug prosecutor. Latin Americans do not need to be reminded that drugs are a menace; and they will not take kindly to the suggestion that defeating drugs is as easy as shutting off a spigot. Americans, for their part, should ponder the sobering fact that Colombia is already the third-largest recipient of American aid, most of which goes toward the war on drugs, and yet coca cultivation in that country is rising.