Crop eradication has been the primary strategy of the U.S. and governments of producer countries of marijuana, coca and opium poppies to reduce the production of illegal drugs at their source.
The U.S. began using crop eradication in the early 1970s, working with Mexico to slash marijuana cultivation. While it also has been employed in the U.S. for marijuana, crop eradication –and its less controversial cousin, alternative development– have been most widely used to cut coca cultivation in Colombia, Peru, Bolivia, and more recently for opium poppies in Mexico and Guatemala.
Coca eradication is considered a controversial measure in source countries as chewing on the leaves of the plant have long been used by many Andean indigenous groups as a part of their cultural traditions, as a way to increase work productivity, a source of nutrition and to stem hunger. Eradication through aerial spraying has been particularly polemic due to the adverse impact on the environment and local populations.
While most producer countries use manual eradication, since the mid-1990s Colombia had been the only government to use aerial spraying until it banned its use in 2015. The decision came after the World Health Organization declared that the herbicide, glyphosate, not only caused environmental damage but cancer in humans.
Similar to interdiction, crop eradication seems to have provided mixed results for reducing the overall amount of cocaine produced and entering a country like the U.S. Even under Plan Colombia, producers were able to find ways to increase crop yield and shift cultivation to other countries like Peru where aerial eradication was absent. In fact, despite the eradication efforts in Colombia, Peru, and Bolivia, by 2007 coca production was higher than in the late 1990s.
Based on the overall results of Plan Colombia, the same study by Daniel Mejia (2010) that estimated the millions spent on interdiction only reduced the amount of cocaine entering the U.S. by 0.29%, predicted each dollar spent on eradication reduced the amount of cocaine reaching the U.S. by 0.007%. However, few such studies very have been conducted and they seem to contradict recent experience. Since the Colombian government eliminated aerial spraying as a part of its efforts to conclude its peace agreement with the FARC, coca production increased 42.5% in 2015 while cocaine production increased 68%.
And despite the seemingly weak outcomes for crop eradication and interdiction, in the case of Plan Colombia, eradication in particular, enabled the Colombian government to regain control over vast territories of land dominated by guerilla groups like the FARC. This had always been a stated policy goal of the Colombian government, which contributed to reducing violence and homicide levels, as well as strengthening the government’s negotiation position with the FARC to begin the peace process.
Therefore, while crop eradication may help a government achieve other policy objectives, given the contradictory conclusions on whether it reduces the amount of cocaine trafficked to consumer countries, U.S. policy makers should attempt to evaluate their effectiveness as specific supply reduction strategies, similar to those to reduce drug demand through prevention education programs, despite their inherent conceptual appeal.