Matt Groff explains why the y-axis on this chart doesn't add up to the $1.5 trillion cited:
In a tight production schedule, I utilized a data set that I thought most accurately illustrated the nature and growth of the costs of the War on Drugs and that data is US federal drug control spending. But the $1.5 trillion figure … accounts for many more costs, including state level costs, prison costs, lost productivity costs due to incarceration and others.
Mike Riggs layers in more data:
According to The Economic Impact of Illicit Drug Use on American Society, last published by the Department of Justice in 2011, enforcing illegal drug laws imposes an annual cost on the American criminal justice system of $56 billion; while incarceration of drug offenders poses an annual cost of $48 billion. That's $104 billion spent annually by states and cities on two aspects of the drug war (and doesn't include treatment, public assistance, and a slew of other costs), compared to roughly $21 billion spent by the federal government. For $1.5 trillion to reflect just federal spending, the federal drug control budget would need to have been $37.5 billion a year, every year, for the last four decades. It's only slightly more than half that this year.