This is an article about the Urabeños mafia in Colombia, and the concern of many people that they may expand as the FARC signs peace accords with the Colombian government and ceases to exist as such. The article kind of gets at the right point. When FARC demobilizes in the wake of the peace accords, there are many risks that depoliticized criminal groups like the Urabeños described in the article will become more powerful. But it's not necessarily because the FARC was a huge drug trafficking organization in its own right. It is instead because the FARC will no longer control certain areas with scant government presence, which means that criminal groups can step in and create de facto control over the area. This would mean that the heretofore independent operators that grew, processed, and shipped cocaine under the tutelage of the FARC would now either join the ranks of larger criminal groups, or be displaced by them. There wouldn't necessarily be more total drug production or trafficking in this case, but it would be under more concentrated control (at least after a period of bloody turf wars as different gangs battled for territory), meaning that there would be new groups consolidating power to threaten the Colombian government. Worst of all for the common people, these new organizations will not have even a nominal concern for the poor, for justice, for economic development, as the FARC did, so they will not be scrupulous about massacring people if they see fit. A similar thing happened as the United Self Defense Forces of Colombia (AUC), an umbrella paramilitary organization, nominally disbanded and was replaced by (or evolved into) the scourge of criminal groups we have today in much of Colombia. The AUC at least had a political agenda, and could thus be somewhat managed and reasoned with. Not so the nihilistic criminal groups.
This brings me to another point. There is hardly a mention of the history of paramilitary groups in Colombia (basically a footnote toward the end of the article, "Oh yeah, the leader of the mafia profiled here was a member of the AUC, which was itself a major drug trafficking organization"), which means that the article misses the key story of the very origins of the criminal groups it profiles. And as such, it totally misses the real issues at stake with the imminent dissolution of the FARC and the possible expansion of groups like the Clan Úsuga (which everyone I know calls the Urabeños). Likewise, the article mistakenly implies that FARC was responsible for most of the Colombian civil war's dead, when the Colombian Center for Historical Memory, the original source for the oft-cited number of 220,000 dead, says that about two thirds of those killed were at the hands of the government and the paramilitaries. So here again the reader comes away knowing less, not more, about the Colombian conflict.
Hence when the author quotes a general saying, "We can’t be naive and think that drug trafficking will end with FARC", they are both being naive already, because FARC really wasn't the major player to begin with. The fact that a Colombian general who should know better is spouting this is indicative of a common party line in the Colombian government. This is reminiscent of the Bush government's stubborn, cynical insistence that Saddam Hussein was a major player in Al Qaeda-style terrorism, which was patently untrue but nicely fit a worldview that suited the government's momentary political purposes.
To my knowledge, FARC is not now nor has it ever been the main drug trafficker in Colombia. It does not control most coastal regions, and in fact doesn't control a whole lot of territory in general. As the article says, FARC has historically not been a producer of cocaine in its own right, but rather "taxes" production and trafficking occuring in territories it controls. Given this, the article's assertions seem reasonable that FARC has often worked in cahoots with different narcotrafficker actors, including parties like the right-wing paramilitaries with which FARC was supposedly at war, since FARC's finance structure was very dependent on "taxes" on the drug trade. But my understanding of the situation remains fundamentally at odds with the author's, since in my mental scheme of FARC's activities, you could not really consider them a narcotrafficking organization in their own right. The fact that some FARC members did indeed become narcotraffickers does not qualify them as an organization dedicated principally to drug trafficking, any more than the involvement of many actors throughout the Colombian government in the drug trade means that the government is itself set up principally to traffic cocaine.
In contrast, it would be fair to classify the right-wing paramilitaries, and even more so their depoliticized "bacrim" (criminal band) descendants, as narcotrafficking organizations, because their primary raison d'etre was and is economic enrichment as an end in itself. The bacrims like the Urabeños described in the article sell drugs (and engage in illegal mining and logging, and human trafficking, and palm oil cultivation, etc.) not to finance any political agenda, but rather simply for their own perpetuation and profit. This to me is a fundamental difference, and accounts for much of my suspicion of the article's claims of FARC's prominence in the Colombian drug trade. How could a bedraggled guerrilla movement barely holding their ground be a more effective organized crime outfit than well-oiled criminal groups dedicated solely to making money (and enjoying the tacit approval of many actors in the local and national governments)? It just doesn't make sense. The article admits as much, but still parrots government of Colombia claims (which I have not found support for beyond the government's constant repetition of them) that FARC accounts for some 60% of Colombia's drug trade.
Anyway, if you're interested in these topics, here is a much more informed, well-written, and nuanced treatment of FARC's involvement in the drug trade. It seems to confirm many of my relatively instinctive impressions.