prohibition has been a net benefit to the US, despite some of its very serious costs.

"It's not in our interest to legalize," Caulkins told me. "Because the benefits the US gets from having the drugs be less available, not advertised, more expensive outweigh the costs for us of crime and violence and corruption in our own borders."

Yes, the drug war helped contribute to mass incarceration — although not as much as you might think, since fewer than one in five prisoners are in for drug offenses. Yes, the black market for drugs gives criminal organizations something to fight over — around 2,000 homicides each year in the US are gang-related, many fueled by drug violence. Yes, the drug war has been used time and time again to erodeuse versus the rates if drugs were legal.

Others may evaluate the costs and benefits differently for the US. As it stands, more than 20,000 people died of illegal drug overdoses in the US in 2013. Caulkins estimated that legalizing hard drugs could increase use by as much as 200 percent, which would lead to more drug abuse and deaths. Whether preventing that is potentially worth more violence over the black market for drugs, the erosion of civil liberties, bigger racial disparities in the criminal justice system, and more incarceration in the US is by and large a personal, philosophical call.

But federal officials and drug policy experts like Caulkins agree the drug war is worth the costs, at least for the US.

One point of caution: Even if prohibition currently