One of Donald Trump's chief campaign promises was to keep Americans safe by restoring "law and order" to their streets. His nomination of Jeff Sessions as attorney general signaled that he intended to follow through on that promise.

This week Sessions issued a new directive for the country's 94 US attorneys to charge criminal suspects with the most serious offense provable against them, including those that would qualify under mandatory minimum sentencing laws.

Sessions' directive effectively rescinds Obama-era guidelines that ignored federal laws and eased sentences for drug offenders. Under Obama, the Justice Department focused on pursuing the most serious crimes and on reducing the number of suspects charged with non-violent drug crimes that would prompt mandatory minimum sentences.

Charging suspects with the most serious crimes they commit will likely mean longer prison sentences for drug offenders. Prosecutors will be able to deviate from the policy but they will be required to obtain approval from the US attorney or an assistant attorney general.

The policy wouldn't target minor drug offenders except those who are linked to violent crime and gangs. It would also target major drug dealers. For example, a mandatory minimum sentence of ten years would typically be sought in cases in which suspects possess large quantities of drugs.

These reforms come at the right time. More than 20 million people in America use illegal drugs, a decades-long high, and a scourge that saps billions from the economy every year, to speak nothing of the lives it ruins. After a steady decline for about two decades, violent crime rose in 35 of America's largest 45 cities in both 2015 and 2016.

Some are portraying this new policy as a major step backward for criminal justice reform. Former Attorney General Eric Holder denounced the new directive as "dumb on crime." An ACLU official called the policy "draconian." But those upset over the move should aim their anger not at Trump or Sessions but at their elected leaders in Congress. As Sessions wrote, the policy is a return to "enforcing the laws that Congress has passed."

There is a strong case to be made against mandatory minimum sentences, but there is no convincing case against prosecuting criminals for the worst offenses they commit. Just think about the contrary idea for a moment; you prosecute them for lesser offenses and let them off the worst ones?

If you don't like a law, change the law, don't pretend it doesn't exist. The rule of law is a prerequisite of a civilized society; lenient sentencing isn't. The directive applies laws passed by Congress. That's as it should be.