About two years ago, the global media discovered "paco," a cheap, highly addictive form of cocaine that was ravaging the impoverished neighborhoods of Buenos Aires. In explaining why paco had become so prevalent, most articles emphasized the widespread poverty that followed Argentina’s economic crisis beginning in 2001. But a NACLA investigation supported by the Samuel Chavkin Investigative Journalism Fund finds that the more important, if infrequently discussed, factor in the paco phenomenon is a shift in cocaine trafficking in the region—largely as a response to the U.S.-led War on Drugs.