Author Gustavo Duncan has no doubt: "Colombia is full of coca," he says. "I assume that this year's coca harvest will be the biggest of all time."

Duncan teaches political science at the private EAFIT University in Medellin. The face of a young Pablo Escobar stares out from one of the books lining the shelves of his living room. Duncan may well be right about the harvest. According to the United Nations, the area of cultivation of coca plants in Colombia doubled between 2013 and 2015. One reason for this was that, as part of the peace negotiations with the FARC, the government refrained from the aerial spraying of coca fields with plant toxins.

Duncan believes that "the FARC is sort of like the government of the coca plantations." It's estimated that around 70 percent of the cultivation area is located in regions that, up till now, have been controlled by the FARC. "An era in the drug trade is coming to an end with the peace process between the Colombian state and the guerrillas," the political scientist says.

The era of the big cartels is over

It's hard to say who will follow in the footsteps of Latin America's oldest guerrilla movement, but there's no shortage of possibilities. After the two big Medellin and Cali cartels were broken up in the mid-1990s, the billion-dollar cocaine trade was shared out among many smaller players. Since then, paramilitaries, guerrillas and organized crime have all enjoyed pieces of the pie.

There's disagreement over how deep the guerrillas' involvement in the cocaine trade actually is. According to the previous Colombian president, Alvaro Uribe, the FARC is "the biggest drug cartel in the world." So far, all that has been confirmed is that the guerrillas financed their war partly by collecting taxes from coca farmers. Whether they were also heavily involved in processing coca plants to manufacture cocaine, or in the lucrative overseas trade, will only become clear when FARC fighters make their statements as part of the peace process, which obliges the rebels to give precise information about their activities.

Cultivation continues

The "Economist" magazine estimates that by 2012 the FARC had already amassed a fortune of 10.5 billion dollars (10.4 billion euros) - although it also had to finance an army of as many as 18,000 men. The decisive question now for Colombia's security is who will fill the newly created power vacuum. "Right now we can't accurately gauge the extent of the influence of the other armed groups," says Duncan. "But if anyone assumes that the FARC's retreat means no more coca will be planted in future, they're wrong."

Bo Mathiasen, the head of the UN Office on Drugs and Crime (UNODC) in Colombia, is much more optimistic. He points out that Colombia has almost half a million officers in the security forces: "So there's great potential to re-establish control and the rule of law in the FARC zones."

'Murder rates could rise'

In the UNODC's headquarters in Bogotá, several floors are devoted to evaluating satellite images, drawing maps and conducting research to find an alternative to coca cultivation. Mathiasen's office works closely with the Colombian security services. They're fairly sure that, in some areas, organized criminals will try to seize control of the crops. "It's possible that in the course of the peace process we may see a rise in the murder rate in certain zones," says the UNODC chief. The government is aware of the risk, he adds, and is taking measures to counter it.

Just last year the Colombian army launched an offensive against the so-called Urabeno cartel, also known as Clan Usuga or Clan del Golfo. A few days ago, security forces arrested another 22 members of the group. Based in the northwest of the country on the Panamanian border, the arrests of high-ranking members in Argentina and Spain suggest that its organization is international.

Cocaine is already cheaper

In contrast to Pablo Escobar's Medellin cartel, for example, the new "narcos" are more modest. "Their business model is to be as discreet and quiet as possible," says Mathiasen. Their structure is also no longer hierarchical but very loosely organized: "It's becoming increasingly difficult to hunt them down," he comments.

Alongside organized crime, there's the country's second, much smaller guerrilla group to consider as well. The ELN will also have an interest in the FARC's region of influence. The ELN is currently conducting exploratory peace talks with the government - but observers say these could drag on for a long time. According to the terms of the peace deal, all FARC fighters must hand in their weapons by the summer.

The UNODC has been supporting farmers for a long time now by providing alternatives to coca cultivation. "But we can only start work when areas are really secure," says Bo Mathiasen. "The biggest challenge now is to re-establish security." With the peace deal in place, UNODC hopes it will soon be able to work with farmers in areas where, until now, such a thing was unthinkable.

However, it will be some time before any success becomes apparent. Initially, Europe and the United States should expect to be flooded with cocaine from the increased area of cultivation. "The price is already dropping," says political scientist Gustavo Duncan. Security services in Europe are already seizing strikingly large quantities of the drug. And Bo Mathiasen doesn't foresee the billion-dollar business winding up in Colombia: "Organized crime is always one step ahead of us," he says.