This year marks the 40th anniversary of President Richard Nixon’s start of the war on drugs, and it now appears that drugs have won.

“We’ve spent a trillion dollars prosecuting the war on drugs,” Norm Stamper, a former police chief of Seattle, told me. “What do we have to show for it? Drugs are more readily available, at lower prices and higher levels of potency. It’s a dismal failure.”

For that reason, he favors legalization of drugs, perhaps by the equivalent of state liquor stores or registered pharmacists. Other experts favor keeping drug production and sales illegal but decriminalizing possession, as some foreign countries have done.

Here in the United States, four decades of drug war have had three consequences:

First, we have vastly increased the proportion of our population in prisons. The United States now incarcerates people at a rate nearly five times the world average. In part, that’s because the number of people in prison for drug offenses rose roughly from 41,000 in 1980 to 500,000 today. Until the war on drugs, our incarceration rate was roughly the same as that of other countries.