EVEN as the fight against drug trafficking focuses on the tide of cocaine flowing north from Latin America, millions of gallons of American-made chemicals used in cocaine and heroin production are quietly being shipped to South American drug producers. Since few Latin nations produce such chemicals as ether or acetone, the drug cartels depend almost entirely on this hidden chemical pipeline, which often runs through third countries such as Mexico and Guatemala.
During the first nine months of this year alone, Colombian police say they seized 1.5 million gallons of such chemicals, enough to produce two-thirds of the world's annual cocaine production. Many of the chemicals (which can fetch 10 times more on the Colombian black market than in the United States) were found in drums displaying US corporate logos.
``It takes two to tango - both coca and chemicals,'' says Rafael Perl, a drug-policy adviser at the Congressional Research Service. He estimates that more than 90 percent of the chemicals used to produce cocaine comes from the US.
The drug lords' chemical lifeline, however, may soon be threatened.
The US Drug Enforcement Administration (DEA) now has greater power to track US chemical exports and penalize companies that knowingly supply drug traffickers, thanks to a new law regulating the exports of 20 ``precursor'' and ``essential'' chemicals. (``Precursor'' chemicals end up as part of the final drug product, while ``essential'' chemicals are vital to the process but don't end up in the drug itself.) (See story page 3.)
Under the law, known as the Chemical Diversion and Trafficking Act of 1988, US firms are required to notify DEA of all regular foreign customers that buy specified ``threshold'' amounts of these chemicals. If the DEA discovers - or even suspects - that the foreign company is diverting chemicals to drug producers, shipments are suspended at once.
For the past six weeks, DEA agents have been rushing to certify the legitimacy of chemical importers around the world, devoting special attention to seven Latin American countries.
By Nov. 1, they will inform US companies of suspected illegitimate customers and begin requiring a 15-day advance notice for large shipments to new or unknown customers.
Not surprisingly, the US is giving intense scrutiny to Mexico, a country trapped by the drug trade on all sides.
Mexico is not only the biggest transshipment point for cocaine, heroin, and marijuana going to drug users in the US. But as the destination for 30 percent of all US chemical exports, it is also considered the largest transit point for the flood of chemicals going to Colombian cocaine rings.
Aside from the US, ``Mexico is the No. 1 exporter of precursor chemicals to South America,'' says one US official, who requested anonymity.
According to a Central Intelligence Agency report circulated last year, Mexican imports of acetone, toluene, and methyl ethyl ketone (MEK) - chemicals that can be used, like ether, to manufacture cocaine - jumped 1,160 percent between 1983 and 1986, even as its economy grew only 2.6 percent.
Overall, the CIA study stated, US exports of these chemicals to Latin America far exceeded the amounts necessary for making explosives, cosmetics, and foam mattresses, items for which they are normally used.
The conclusion was inescapable: Drug traffickers must be siphoning off enormous amounts of chemicals to produce heroin and cocaine.
The chemicals have been easy to obtain. Even after Colombia imposed strict controls on ether and acetone imports in 1982, the Colombian cocaine cartels were able to construct a network of chemical distributors throughout Latin America and the Caribbean that could supply ether and its substitutes, according to international drug experts.
Just as the Colombians began infiltrating Mexico a few years ago with their cocaine-trafficking network, they also established a chemical-diversion racket here, using small shipments of chemicals, dummy companies, and multiple suppliers to disguise their identities.
It is estimated that more than 35 percent of the several hundred Mexican companies that handle precursor chemicals are suspect enterprises, about half of which are diverting precursor chemicals to South America, drug experts estimate.
The cash-strapped Mexican government, seeing now that drugs are no longer just a ``gringo'' concern, is putting more energy and resources into the drug fight than ever before.
So far this year, Mexican agents have captured 23 tons of cocaine, compared to 33 tons netted over the preceding 10 years.
Although Mexican officials contend that Mexico already has laws that minimize the problem of precursor chemicals, they agree the new US law represents an ``added effort'' to attack a crucial link in the drug chain.
``Just as we have programs to eradicate illicit crops, break up organizations, and prevent money laundering, now it is indispensable to control and watch out for precursor chemicals,'' says Enrique Arenal, director of the attorney general's Office of International Affairs.
But even though official US-Mexico cooperation on drug matters has improved dramatically, the DEA still faces challenges implementing the new law - and finding the right, ``chemistry'' in dealing with the Mexican government.
US officials worry that the DEA will have a hard time certifying companies in a country like Mexico, with its informal business practices, complex bureaucracy, and strong sense of nationalism.
Nevertheless, US officials say they were pleased by the Mexican government's lightning-fast reaction to the DEA's first tip about a suspect company three weeks ago.
Another concern is the lack of sufficient personnel.
``My fear is that we'll be overwhelmed,'' says a US official, lamenting the fact that most DEA offices only have one agent working on chemical diversions. ``If we only have five companies to check each month, we can take care of it with one officer. But if we have to deal with 100 a month,'' he says, sliding easily into a drug metaphor, ``we'll OD [over dose] on it.''
But with rivals as ruthless as the Colombian cocaine lords, the DEA's greatest challenge may be still to come.
The diversion law ``will shut down those transactions that have been going on openly,'' says Garrity Baker, director of international affairs for the Chemical Manufacturers Association, which has collaborated closely in shaping and implementing the law.
``But illegal drug-making is so lucrative that traffickers will do whatever they can to get their hands on these chemicals,'' Mr. Baker adds.