The U.S. Justice Department recently informed federal prosecutors in 20 states and the District of Columbia that it will no longer sue to block laws that decriminalize possession of marijuana at the state level. It’s a good call.

Last year, voters in Colorado and Washington approved laws decriminalizing possession of small amounts of marijuana for personal use; 18 states have made the medicinal use of the drug legal.

Yet such possession has remained a federal crime with the threat of federal action. This untenable situation has caught ordinary Americans in the middle.

The Justice Department’s memo to federal prosecutors cited “limited prosecutorial resources” as the reason not to argue with states that have decriminalized possession. It was also an acknowledgment that it is time to prioritize the drug-related crimes that the federal government will continue to pursue zealously.

The department is clear about what it expects from states, now that once-threatened lawsuits won’t be forthcoming. The federal government is insisting that regulations aimed at preventing sales to minors must be a priority.

Further, robust and practical plans to deal with the interstate movement of marijuana, gangs, cartels, turf wars, and illicit profits must be in place. Few Americans will argue with that.

Advocates of liberalized marijuana laws are encouraged by the Justice Department’s latest moves. Expect a long, strange trip as reefer madness is cautiously set aside. In socially conservative Ohio, that trip will be longer still.

First Published September 10, 2013, 11:33 p.m.