The Sentencing Project has crunched Bureau of Prisons numbers and found some relatively good news, finally: a significant drop in the number of blacks locked up for drug offenses. Between 1999 and 2005, the number of black drug offenders in state prisons plunged 21.6 percent, by about 30,000 people. In a countering, negative trend, white incarceration for drug crimes shot up 42.6 percent.

So what’s going on? Lots.

First, the part that’s simple to explain: White drug incarceration is skyrocketing as the “war on drugs” shifts its focus from crack to crystal methamphetamines, which is a drug disproportionately used and sold in poor and working-class white communities. Throughout the 1980s and 1990s, national headlines and federal money spurred localized zeal for crack arrests, and the same forces are now demanding intervention into rural white communities to chase meth.

The decline in black drug offenders, on the other hand, is the result of several trends, some positive and some not.

As the Sentencing Project details, a big part of the decline is structural. Crack busts drove drug arrests and convictions in black neighborhoods. But crack long ago faded from the drug market, if not the popular culture. Moreover, the large-scale drug dealing businesses—and that’s what they are, like it or not—have adapted their distribution channels in response to the cops’ military-style sweeps of the ’80s and ’90s. Here’s how John Jay College of Criminal Justice scholar Ric Curtis once explained the shift to me:

“Many of the businesses had been modeled on the McDonald's or Wal-Mart style of operation. … They had all these street-level functionaries that were just interchangeable cogs for them, but they were getting arrested in extraordinary numbers. … So eventually they said, 'You know what? Fuck this. It's too much of a pain in the ass. We're gonna downsize. We'll retain management and lop off labor. And management is gonna go to a new style of business.’”

The new style of business, as the Sentencing Project notes, abandons the street corner and instead focuses on delivery to regular, known clients. So the big players moved the market off the street and out of the cops’ hair. Cynical as it sounds, that’s actually something of a policing victory—it means fewer turf wars and safer neighborhoods. (Sure, it literally sweeps the problem out of sight, but it certainly doesn’t get rid of drug use and -dealing, and in no way mitigates the damage both wreak upon individuals, families and communities.) In any case, the new distribution system means fewer black arrests, fewer black convictions and fewer black inmates.

It also reinforces a broader failure in our criminal justice response to drugs: We’ve locked up hordes of low-level, nonviolent “cogs” instead of the people who built, ran and profited from drug businesses. In recent years, this fact has sunk in for even the most ardent drug warriors. Federal District Court Judge Reggie Walton—the tough-on-crime, Republican appointee who dropped the hammer on Lewis “Scooter” Libby—has become one of the most outspoken reform advocates, for instance. Here’s what he told me last spring:

I’m not suggesting that people who sell drugs don’t cause harm to communities and therefore should not be punished. But I think it doesn’t make sense to spend the amount of money we spend to lock up somebody for an extended period of time when a lot lesser sentence would probably serve the same objective, especially if you’re talking about a low-level street dealer.

This shift in thinking among the drug-war generals, and the proliferation of drug courts—in which nonviolent offenders are put in treatment and presented a range of alternatives to jail—may be another part of what’s slowed the march of blacks into state prisons.

All of this laid to the side, the welcome progress the Sentencing Project has documented simultaneously reinforces the wild havoc the drug war has wrought. African Americans represent less than 15 percent of drug users and 12 percent of the overall population. Yet, even after the huge decline in recent years, blacks still accounted for 45 percent of drug offenders in state prison in 2005. Moreover, the feds appear to have picked up the states’ slack.

The sobering fact remains that America incarcerates more people than any country in the world. Last year, we spent $45 billion to keep 7.2 million people in the prison system. Huge numbers of those people are forever blocked from becoming productive members of society—they can’t get jobs, can’t get student financial aid, and in many cases can’t vote. The prison-industrial complex has also crippled state budgets—while doing nothing to impact drug use. That’s neither productive nor sustainable.