Back in the 1980s, when crack and its associated violence were sweeping through American cities, Congress responded by imposing drastic and often mandatory penalties, and Jeff Sessions was the U.S. attorney for southern Alabama. It was the height of “The Drug War.” And before long, with prisons overflowing and disproportionate sentences being imposed, many in law enforcement concluded that the “lock ’em all up” approach was an overreaction. Better alternatives existed, and both Congress and the Obama administration dialed back The Drug War.

On Thursday, the former federal prosecutor from Alabama took the first steps toward a return to The Drug War. The now-attorney general of the United States rescinded a policy issued by his predecessor Eric Holder instructing federal prosecutors to avoid charges with long mandatory  minimums where appropriate. Instead, Sessions instructed, prosecutors should “charge and pursue the most serious, readily provable offense” And to be clear, Sessions wrote, “By definition, the most serious offenses are those that carry that most substantial [sentencing] guidelines sentence, including mandatory minimum sentences.”

Many people in the criminal justice system thought federal prosecution had evolved beyond this mindset. Sentencing guidelines were changed from mandatory to advisory, some mandatory minimums were erased and the disparity between crack and powder cocaine sentences was reduced. Drug treatment was seen as a more effective alternative to heavy incarceration. Sessions’ push for maximum penalties brought immediate groans of dismay from many quarters, including some former prosecutors.

John Walsh, the former U.S. attorney for Colorado and past chair of the Attorney General’s Advisory Committee of U.S. Attorneys in 2015-16, acknowledged that crime was rising in some parts of the country. “But this policy rests on the misapprehension that charging more severely across the board will have the effect of reducing specific hot spots of crime,” Walsh said. “That has to be addressed in a targeted, focused way. Raising the severity of sentencing across the board, in every U.S. attorney’s office across the country, is not going to have that effect.”

“Seeking the maximum possible penalty in every case isn’t justice,” said Barry Pollack, president of the National Association of Criminal Defense Lawyers. “It’s vengeance. This is a return to policies that have been tried and failed repeatedly. It will waste great resources going after low-level, non-violent offenders. And it will continue the misguided effort to combat drug abuse with incarceration rather than treatment.”

Sessions’ new policy does allow federal prosecutors some discretion in not seeking the highest charge or the longest sentence, with the approval of supervisors. But Walsh noted that in many parts of the country, that may only enable prosecutors to adjust to the leanings of their local federal bench, some of whom may favor stiff sentencing, and some who may not. In the eastern district of Tennessee, where former federal prosecutor Steven H. Cook, a supporter of the return to stiff sentencing, worked, “you’re likely to see sentences skyrocket,” Walsh said. In places such as Los Angeles and San Francisco, where judges take a more liberal approach, “you’re going to have U.S. attorneys wrestling with this with hostile judges.”

Some in the justice system have argued that the mass incarceration of the ’80s and ’90s was a good thing because it helped lead to the ensuing decline in the crime rate nationwide. Sessions’ move could be an attempt to reinstitute that philosophy.

Pollack responded, “Study after study has shown that mass incarceration was not the reason for the decreases that we saw in some areas in crime rate. Even if you could make the argument that locking everybody up reduces the crime rate, it still makes no sense from a public policy perspective. It’s like a dragnet approach that ensnares non-violent offenders and violent offenders, simply clogs the system while diverting resources from pursuing those individuals whose crimes do merit severe sentences.”

Walsh agreed. “The cost to the U.S., and the diversion of resources to the federal Bureau of Prisons and other jails, really distorted the way law enforcement works in this country.” With more discretion in prosecution, Walsh said, “We can be more focused and more fair because we’re not rounding up whole groups of people and locking them up for decades.”

Former Utah U.S. Attorney Brett Tolman joined in with Walsh, saying, “To maintain law and order, we need effective policing and prosecution. The Justice Department’s shift to prosecuting and incarcerating more offenders, including low-level and drug offenders, is an ineffective way to protect public safety. Decades of experience shows we cannot arrest and incarcerate our way out of America’s drug problem.”

A number of legal affairs groups also weighed in. Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund, issued a statement which said that, “When President Trump asked black Americans what we have to lose by electing him, the answer is all the gains we’ve made in advancing justice and fairness. By reinstating a long-discredited policy of harshly punishing individuals who commit low-level, nonviolent drug offenses, Attorney General Sessions has turned back the clock on our criminal justice system, ensuring it will continue to disproportionately punish black people, harming our communities and widening painful divides in our society.”

Maria McFarland Sánchez-Moreno, co-director of Human Rights Watch’s US Program, said that “Sessions is willfully ignoring the facts about the cruelty, waste, and ineffectiveness of the ‘tough on crime’ policies of the 1980s and 90s. He seems intent on locking up as many people as possible, for as long as possible, no matter how old or minor the offenses, or how devastating his prosecution binge is to those affected and their families.”

Sessions’s memo can be seen here.