Although Iraq has long been a happy hunting ground for archeologists, experts now fear that war in the Middle East will further ruin what has become an unholy mess.

In a fervent plea published in Friday's Science magazine, leading scholars begged armies and governments to safeguard as many archeological sites as possible, and shut off major looting of antiquities that is already under way in Iraq.

"Under threat is an important part of the world's cultural heritage," said McGuire Gibson, president of the American Association for Research in Baghdad and professor at the University of Chicago.

Thousands of archeological sites, many of them as yet unexplored, may be decimated in tank battles, by bombing, and especially by looting, he warned.

Most in need of protection is the Iraq National Museum in Baghdad, Gibson said, plus the museum in Mosul. "Both are close to government buildings that were hit by 'smart bombs' in the Gulf War (of 1991)," and even if both escape the bombs, "fighting will render both vulnerable to looting."

Because of the peril, a statement signed by leading archeologists around the world, published alongside Gibson's article, admonished: "The signatories of this letter urge all governments to recognize that fragile cultural heritage is inevitably damaged by warfare . . . that irreparable losses . . . to all humanity are caused by the destruction of cultural sites, monuments and works of art."

Guarding Iraq's antiquities -- and the people working with them -- is vital, according to archeologist Elizabeth Stone at the State University at Stony Brook. "Among the various early civilizations we know of, [Iraq] is by far the earliest and the most knowable." People who lived and worked there 5,000 years ago "lived in these large, spread-out cities, some of which have been excavated, and they wrote on clay. They wrote about everything, and the writing was not restricted to a few people and a few topics."

Indeed, because hundreds of thousands of hard clay writing tablets have been found, "we have intimate knowledge of these people who lived 4,000 and 5,000 years ago," she said. "We don't have that anywhere else."

Iraq has always been extraordinarily important for archeology. Known as the Fertile Crescent, it was the first cradle of civilization, the place where ancient tribes progressed to become major populations such as Sumerians, Akkadians, Babylonians, Assyrians and others.

Because those early cultures advanced rapidly, Stone said, the Fertile Crescent is where the first writing, the first wheels, the first cities and the first specialized professionals -- experts in the arts and crafts -- arose. Egypt and China developed later.

Unlike many artifact-rich countries, the archeologists said, Iraq stood as a world-class model for finding, preserving and displaying ancient cultural artifacts. Scholars were welcomed to study ancient objects.

During fighting, Stone added, the Baghdad Museum "should be seen as a relatively lightly guarded treasure house, right in the middle of Baghdad. We are concerned about looting because there's an enormous number of artifacts [in the museum], and because [the people in] what was once a super antiquities department will be there trying to defend it with their lives."

But avoiding archeological sites will be difficult, if not impossible. Gibson, Stone and others estimate there may be 100,000 known and potential dig sites, most of which have never been explored. Worse, all large mounds seen in the desert are invariably the remnants of ancient settlements, and "armies dig in on high ground," Gibson said, destroying artifacts.

Gibson said that before the Gulf War erupted, soon after Iraq invaded Kuwait in 1991, the Iraqi authorities "had an enviable record of protecting (Iraq's) antiquities and cultural heritage. The Department of Antiquities, backed by an exemplary Antiquities Law, had control of all archeological sites and artifacts."

But during the Gulf War, "nine of the 13 regional museums in the south and north were raided by mobs, who smashed exhibits, stole antiquities and sometimes set fire to the buildings," Gibson said. Very little of what was lost has been recovered.

Also, because of the United Nations' economic embargo, the impact on security has been devastating. "There has been an increasing pace of looting of archeological sites followed by large-scale smuggling out of objects to feed the voracious international antiquities market," Gibson said.