BY JUAN O. TAMAYO

 BOGOTA, Colombia -- A survey of Colombia's coca fields sponsored by a U.N. agency suggests they are far larger than previously believed -- one-third the size of Miami-Dade County. But U.S. officials say they doubt the estimate because of the methods used.

 The survey by the U.N. Drug Control Program, or UNDCP, estimated Colombia's coca fields at 402,610 acres, compared to Miami-Dade's 1.3 million acres, based on images taken Aug. 31 from one U.S. and two French commercial satellites. The results were made public in mid-May, provoking a debate over the efficacy of U.S. counter-narcotics policies.

 The total is enough to make 800 to 900 tons of cocaine -- U.S. consumption is estimated at 269 tons a year -- but represents only a 2 percent growth from the results of a mid-1999 trial run of the satellites hired for the project.

 ``In other words, the year 2000 allows us to see a trend toward the stabilization or braking in the growth of the cultivation,'' said the Colombian government's National Narcotics Council when it released the study.

 U.N. and U.S. officials cautioned that their figures cannot be compared to the latest, much smaller U.S. estimates announced in March because of the different
 technology used and times involved.

 Washington's assessments of coca cultivation are crafted by CIA analysts from data gathered not only by satellites, but also by surveillance aircraft and other methods during the last three months of each year -- as opposed to the one-day blanket coverage by satellites used by the U.N. study.

 ``This report says only that the area is very large,'' said Klaus Nyholm, head of the U.N. Drug Control Program's Bogotá office.

 LIVELY DEBATE

 But the report has already added to a heated debate in Washington over U.S. counter-drug policies, which rely heavily on increased military aid to Colombia and the aerial spraying of coca fields with a chemical weedkiller.

 ``This means we bit off more coca than we can chew,'' said Sanho Tree, director of the Drug Policy Project at the Institute for Policy Studies, a liberal think-tank in
 Washington. ``The options now are either to dramatically escalate this war or face the reality that this is a war we cannot win.''

 Countered Stephen Johnson, drug policy analyst with the conservative Heritage Foundation in Washington: ``This is a clarion call that we need to do more on the supply side of the problem.''

 The latest U.S. estimate of Colombia's coca acreage pegged the year 2000 total at 326,000 acres, an 11 percent increase over 1999. Previous U.S. estimates had put growth from 1998 to 1999 at 20 percent.

 Rand Beers, assistant secretary of state for international narcotics and law enforcement, said in Washington recently that it would be premature to assume the U.N.
 figures pointed to a failure of the U.S. aerial spraying in Colombia because of the different methodology.

 A $1.3 billion U.S. aid package approved last summer for the counter-narcotics and nation-building effort known as Plan Colombia included $115 million for stepped up aerial spraying.

 ``It may too early to say that Plan Colombia is not working . . . but the U.N. study certainly shows the problem is far bigger than we thought,'' said Adam Isacson of the liberal Center for International Policy in Washington.

 VARYING ESTIMATES

 UNDCP agreed in 1999 to finance the satellite surveys because of the huge gaps between the CIA and Colombian police estimates over the years, with the CIA figures usually more conservative than the Colombian figures.

 Colombian police officials said that while the UNDCP figures on size and growth rates cannot be compared to the U.S. or Colombian police estimates, they do provide interesting insights.

 The UNDCP-estimated increase of 7,410 acres between the trial run in mid-1999 and the survey Aug. 31 came despite the 143,000 acres that police reported spraying -- and eradicating -- in all of last year, they noted.

 And the UNDCP's higher acreage estimate should cast doubt on U.S. estimates of the percentage of Colombian cocaine exports intercepted by U.S. agencies -- in effect, their ``success rate'' in the war on drugs.

 Further complicating the picture, Colombia's military and police found a huge increase in coca acreage when they launched an intense spraying campaign Dec. 19 in the southern state of Putumayo, believed to be home to about 50 percent of the country's coca production.

 ``In one area we had estimated 6,175 acres, but found 14,820 acres'' Gen. Mario Montoya, the region's top military commander, told The Herald in a recent interview. ``And it was the same story everywhere we went.''

 EXPANDED SPRAYING

 The seven-week air eradication campaign, the first effort financed from the $115 million in U.S. aid, sprayed some 74,000 acres with glyphosate, a weed killer sold under the trademark of Roundup.

 Police reported spraying an additional 94,000 acres in the first four months of this year, and U.S. Ambassador Anne Patterson said recently that she expected this year's total to hit 198,000 acres.

 U.S. officials have steadily cautioned that the aerial spraying campaign will need time to gear up.

 The $115 million included money to buy five new crop dusters, which have yet to arrive in Colombia.

 ``It will take until 2003 before we get ahead of the [new plantings] curve,'' one government narcotics analyst in Washington said.

 ``Until then, it will be hard slogging and all uphill.''

                                    © 2001