Ending the war on drugs wouldn’t end mass incarceration. But it would help.

Only a small portion of the prison population — about one-fifth — is made up of drug offenders. Over the past year, multiple reporters, including me, have written about this fact to point out that ending the war on drugs wouldn’t end mass incarceration.

But a new analysis by the Urban Institute shows why reforming drug offenses still matters a lot.

As authors Ryan King, Bryce Peterson, Brian Elderbroom, and Samuel Taxy point out, the federal prison system is still the country’s single largest incarcerator — at nearly 206,000 inmates, federal prisons house roughly 50,000 more people than Texas, the second largest imprisoner in the US. And about half of federal prisoners are classified as drug offenders — a stark contrast to the 15.7 percent of state prisoners who are in for drug offenses. So reducing penalties for drug offenses would have a significant impact on the federal prison population, even if it wouldn’t do much for state prisons, which house about 87 percent of America’s prison inmates.

Urban’s interactive chart demonstrates this. Reducing the length of sentences for drug traffickers by 50 percent would cut the federal prison population by roughly 18 percent by September 2023. Doing the same for violent offenses would only cut the federal prison population by 1 percent. Clearly, reforming drug offenses is a much more sensible target for policymakers focused on federal prisons.

Urban’s graphic also only gets to the direct consequences of reforming or ending the war on drugs. There are indirect benefits, too: The drug war has created a huge black market for drugs that has provided billions in revenue to gangs and other criminal organizations around the world. These groups, in turn, carry out violent operations to ensure they keep their stranglehold over the market. The drug war, in other words, gives these groups a reason to commit violent crime. So ending the war on drugs could, at least in theory, help bring down violent crime as well. (Although such a drastic step would need to be balanced with the risk of making drugs more accessible and culturally acceptable.)

So it’s very much true that ending the war on drugs — or at least reforming sentences attached to drugs — wouldn’t be enough to end mass incarceration, particularly at the state level. But it would help, especially at the federal level. Getting that nuance right is important as talks of criminal justice reform continue at every level of government.