THE ITALIAN government's request for U.S. help in protecting its cultural heritage by cracking down on the import of antiquities is a reminder of a worldwide problem that technology has made worse. That problem is the boom in the looting of ancient objects, whether from illicit excavations, burglarized museums or plain vandalism. Italy wants the United States to impose import bans on a broad category of objects -- everything from statuary to coins -- dating from before the 4th century A.D.

A request for such import restrictions is an admission that Italy, like many art-rich countries, cannot adequately police its sites at home. High-powered and easily available metal detectors and undersea salvage equipment long since tilted the worldwide balance toward looters and away from the usually inadequate security provided at cultural sites outside major cities. The profit to be made from an avid and growing collectors' market has drawn in international organized crime groups, with their yet greater resources for circumventing law enforcement at the source. Requests for restrictions -- which are evaluated by a State Department advisory committee -- are fairly common, but the breadth of the Italian one is new and has drawn criticism from many in the legitimate art market. (The committee is free to grant a narrower version of the request.)

Italy is far from the most victimized country in this regard -- places such as Cambodia, Tibet and Eastern Europe suffer more comprehensive looting -- but Italy is exceptionally rich in antiquities. Its laws also give a firmer basis than the laws of other nations for recovering artifacts under international conventions, because a 1939 law declared all Italian cultural patrimony to be the property of the state, making it easier to classify looted objects as stolen property.

But the reason to curb looting is not merely legal. Knowledge of past civilizations and prehistory, in great measure drawn from archaeology, is far from complete; important finds continue to fill gaps and lead to revision of long-held theories. But the scientists with their improved methods cannot stay ahead of the looters with theirs. Museums in the past decade have shucked their earlier reluctance to look closely at provenance and have begun returning objects and refusing to buy questionable ones. The art trade is moving that way too, but far more slowly. Import controls aren't the whole answer, but they can be a useful tool in speeding things up.