I got the feeling in Medellin that its "renaissance" was in a large part due to it being a center of the drug war. It brought a lot of violence but it also brought a tremendous amount of wealth into the city, which put it in good stead once the war ended.
Indeed. It's impossible to analyze Colombia's macroeconomics without having into account drug dealing. At some point, I know that this activity represented 3% of the GDP.
However,
Lots of colombian corporate giants where founded in the '40s in Medellín. Today, out of the 10 most valuable colombian companies, 6 are headquartered in Medellín. These companies (not in order) are Éxito (retail), Argos (concrete), EEPM (utilities), Sura (insurance), Nutresa (food) and Isa (utilities).
In conclusion the city was heavily industrialized before the cartel, but the drug war did indeed bring some money that got managed for good in later decades.
