Vox - There is one sentence in Sean Penn's weird interview with Joaquín "El Chapo" Guzmán, the head of the huge Sinaloa drug cartel in Mexico, that explains the big problem with the war on drugs: When asked about whether he's responsible for the drug addiction in the world, Guzmán responds, "No, that is false, because the day I don't exist, it's not going to decrease in any way at all."
...Chances are Guzmán's capture, like the captures and deaths of so many drug lords before him, will do nothing to stop the flow of drugs into the US. And even Guzmán knows it. Related How one renegade country could unravel America's war on drugs
... In late 2011, the US Department of Homeland Security issued a memo stating this outright, concluding that "there is no perceptible pattern that correlates either a decrease or increase in drug seizures due to the removal of key [drug trafficking organization] personnel."
... The drug trade is too profitable to go away. The problem is what's known as the "hydra effect": When one source of drugs shuts down, another takes its place. The name comes from the mythological hydra, a beast that, in some versions of the story, grew another head when its previous one was cut off.
Since drugs are so lucrative, drug producers and traffickers don't just cease to exist when governments detain or kill them. The business is so profitable that someone will always be there, willing to replace defunct organizations or leaders. In this case, the fall of El Chapo won't lead to the end of the drug trade, but instead will lead to someone else replacing him as head of the Sinaloa Cartel. And even if the Sinaloa Cartel collapsed — a very unlikely event — another drug trafficking organization would take its place.
The effect is similar to the "balloon effect," when cracking down on the drug trade in one area simply moves it to another area — sort of like pushing down on a balloon can simply move the air to other parts of the balloon. This effect has been documented all around the world, including Colombia, Mexico, Venezuela, Ecuador, and West Africa.