The North American Free Trade Agreement took effect 25 years ago this week, boosting trade across the United States, Canada, and Mexico. But it also helped fuel the modern drug trade.NAFTA phased out tariffs across North America, making it easier for freight trucks to cross the border. Between 1994 and 2001, the number of trucks crossing into the U.S. from Mexico nearly doubled to roughly 4.3 million per year. U.S. border officials only inspected about 10 percent of these trucks, leaving a big opening for drug traffickers. A decade after NAFTA, 90 percent of Colombian cocaine was smuggled through the southwest border. Mexico, which had always been the Walmart of marijuana and heroin, quickly became, as the Wall Street Journal put it, the FedEx of the cocaine business. Economists disagree about NAFTA’s ultimate impact on the North American economy. And the future of the trade pact will be up for debate in 2019 when Congress decides whether to ratify its replacement, the United States Mexico Canada Agreement, or USMCA.But what’s indisputable is NAFTA’s impact on the global drug trade and on the massive wealth and power accumulated by Mexican cartels and kingpins, like Sinaloa cartel leader Joaquín “El Chapo” Guzmán. (Listen to the full story of El Chapo's trial in our podcast "Chapo: Kingpin on Trial," available for free exclusively on Spotify.)This segment originally aired Jan. 3, 2019, on VICE News Tonight on HBO.