How did drug trafficking expand in Colombia after 1975?

Following major interdiction efforts in Mexico in 1975, Colombia’s role as a supplier in the international drug market expanded rapidly. Initially, the country became a primary source for marijuana imported into the United States.12

Drug leaders, particularly those based in Medellín, subsequently used profits from the marijuana trade to diversify into cocaine trafficking. This shift facilitated the evolution of large, Mafia-like drug cartels, most notably those in Medellín, led by Pablo Escobar, and in Cali. Trafficking methods also advanced, moving from small-scale transport to the shipment of large quantities via boats and low-flying aircraft.12

By the 1980s and 1990s, the drug trade had become a potent factor in the national economy, at times exceeding the value of legal exports. As these organizations grew wealthier, they utilized terror to increase their bargaining power with the government, leading to significant political violence and instability. By the late 1990s, the industry further expanded to include opium poppy cultivation and heroin trafficking.312