When the ancient Aztecs, Mayans and Zapotecs died, they often were buried with treasures of this world to ease passage into the next. Thus the classic stone pyramids and the sacrificial wells of Mexico have yielded treasures of gold, jade, turquoise and obsidian--treasures that teach visitors to contemporary museums about Indian civilization before the coming of the Spaniards. Thieves who stole some of those treasures from Mexico City's splendid National Museum of Anthropology on Christmas Eve stole more than objects of monetary value; they took part of the nation's cultural heritage.
But thieves don't operate in a vacuum. No reputable museum or private collector would buy the famous jade mask from Palenque or the gold objects retrieved from the cenote, or well, at Chichen Itza. There is, however, a brisk trade in stolen pre-Columbian art that has not been curbed despite tougher export policies in Central and South American countries.
In 1973 the United States tried to curb the traffic in stolen art by prohibiting the importation of large works, such as murals and stone relief sculptures. But the importation of smaller objects that are easier to carry is not yet regulated, and traffic in those items is increasing, according to Clemency Coggins of Harvard's Peabody Museum.
The thefts from museums and ancient graves will continue until governments of the world make it harder for thieves to profit from cultural looting.