If people are afraid of dying if they do drugs , they will not usually do it. A great example of this is in Singapore. In Singapore possessing drugs results in the death penalty, no questions asked. And look at the results, only 0.0013% of the population use drugs. Compare that with the US, 8.9% percent of the population their uses drugs. Over 500 times as much people use drugs in the US compared to Singapore. Singapore is also located very close to an area known as the Golden Triangle. The Golden triangle is a hub for opium production. Even though Singapore is located by one of the largest opium producing areas, it still has an amazingly low drug rates. If similar laws would be erected in the US, I doubt that kids would consider smoking pot because they would know they would be taking their turn sitting on Ol' Sparky.
Whether its a drug trafficker or a drug user, an example needs to be set. Target the drug users, and show that using drugs is unacceptable. Reduce the amount of drug users, and have less clients for the drug traffickers. If done effectively and properly, the image of being a drug user can drastically change, and make it undesirable.
Until drugs are legalized and the stigma of illegal drugs is eliminated, drug traffickers will always find a way to get their merchandise into the hands of consumers. It's just like laws preventing mass shootings--no matter how strict a law is when it tries to prevent a crime, someone will always find a way to break the law and find loopholes.