THE walled city of Cartagena on Colombia's Caribbean coast was for centuries the main port for export of the Spanish Empire's precious metals from the New World. Today (Feb. 15) it is the scene of a summit meeting on the white gold of the late 20th century - the Western hemisphere's $120 billion-a-year cocaine trade. President Bush is due to hold up to seven hours of talks in Cartagena with his counterparts from the three main drug-producing countries of the Andes - Virgilio Barco Vargas of Colombia, Alan Garc'ia P'erez of Peru, and Jaime Paz Zamora of Bolivia. The summit is expected to end with the signing of a document setting out ``understandings'' for coordinated action against the cocaine trade.
These include commitments by the United States to finance development of legal crops as an alternative to coca. In return, Andean countries will step up police action against the drug trade and take steps to reduce the coca harvest, say diplomatic sources familiar with the draft agreement, which has not been made public.
The Andean presidents are also expected to stress to Mr. Bush their opposition to any combat role for US troops in drug-control programs in their countries and to press for increased access to the US market for their legal exports. Mr. Barco will likely raise the issue of the collapse of the International Coffee Agreement (in which US action played a part), which has cost Colombia $187 million in export income in seven months.
The US December invasion of Panama and a Pentagon attempt last month to send a aircraft carriers to patrol the Colombian coast made the Andean countries wary of threats to sovereignty under the guise of Washington's ``war on drugs.'' Still, Bush may raise the idea of using US military to cast a ``radar net'' over Colombia to track cocaine-carrying aircraft.
After a decade of US finger-pointing at drug-producer countries, the Bush administration says it is now emphasizing action against all the links in the drug chain, from the Andean coca field to the street corners of US cities.
But Barco in particular - whose recent campaign against Colombia's drug rings has achieved some success, but at a cost of almost 200 dead in terrorist bombings - is likely to insist on stronger US measures to control both drug consumption and the export of arms and chemicals used in drug processing.
For security reasons, Bush was due to land in Air Force One in Barranquilla, 110 miles northeast of Cartagena, before being whisked by helicopter to the summit venue - the Presidential Guest House, a retreat on the peninsula jutting into Cartagena bay. The peninsula has been sealed off by thousands of Colombian troops and hundreds of US security agents.
Despite reports that drug traffickers might use missiles to attack the summit, both Colombian and US officials here dismiss the security threat as ``minimal.''
``The real story'' behind the summit ``is the degree to which people are beginning to talk about [the drug problem] in similar ways,'' a US official here says.
The idea for the summit arose from the US National Drug Control Strategy, launched by Bush in September. After the Andean presidents issued a formal invitation to Bush in October, months of talks between officials from the four countries ended with a draft agreement last Friday.
The Bush plan envisages an increase in US spending on drug-control programs in the Andes, from less than $100 million in 1989 to $476 million in 1991. The Cartagena agreement seeks to provide a framework under which that money will be spent. It will be followed by bilateral accords between the US and each of the three Andean countries.
Some Latin American critics say the agreement threatens to ``militarize'' the drug issue, a move they say could bring increased social conflict and hurt the slow consolidation of democracy, particularly in Peru and Bolivia. These two nations are responsible for almost 90 percent of world coca-leaf production. And their governments have traditionally seen the drug issue as a ``development'' problem.
The bulk of US aid in 1990 is earmarked for law enforcement programs, including equipment and training for the cash-strapped armed forces of the Andean countries.
In Peru, US diplomats say the military aid is intended to help the Army fight the Shining Path, a Maoist guerrilla movement whose presence in the Upper Huallaga Valley - the source of half the world's coca - has impeded drug-control efforts by the Peruvian police and agents from the US Drug Enforcement Administration.
But many Peruvian experts doubt the country can fight the guerrillas and the drug trade at the same time. They cite events in the Huallaga Valley last year, when the Army took charge after guerrillas overran a 67-strong police post in Uchiza, a drug export center. In an attempt to win over the local population, Brig. Gen. Alberto Arceniega ordered the drug police to stay away and is promoting voluntary efforts to substitute coca with other crops.
The Cartagena agreement will likely mark a new departure for US drug-control policy in the Andes. From 1991, US aid is set to include a strong economic development component to support legal options to growing coca. US policymakers say forcible eradication of coca fields - once the cornerstone of their policy - should be assessed case by case, taking account of the political costs.
Although unofficial drafts of the Cartagena agreement leaked to the press suggest that Washington will offer to improve access to the US market for Andean exports, the presidents are likely to insist on tighter commitments.
``No peasant farmer is going to stop sowing coca while he has no assured market for the sale of coffee, cocoa, sugar cane, or palm oil,'' Peru's President Garc'ia said last week. This view is shared by Bolivia, South America's poorest country, where the cocaine trade brings in more dollars than total legal exports.
``Bolivia doesn't want just to substitute crops - it wants to substitute the income, employment, and exports'' that coca provides, says Roberto Camacho, an adviser to President Zamora.