Marijuana advocates in California and elsewhere cheered the Obama administration's announcement Thursday that it would not interfere with new laws in Colorado and Washington state permitting recreational use of cannabis.
But the advocates cautioned there is still a ways to go before legalization.
Dale Gieringer, a leading marijuana advocate in California, said he is encouraged by the new U.S. Justice Department memo, but he notes he has been encouraged by past memos only to see federal enforcement increase.
"There are some weasel words in this," he said. "They're not going to make a priority to do something, but that doesn't mean they won't do it."
The memo written by Deputy Atty. Gen. James M. Cole is a sharp turn from the last memo he wrote in 2011, in which he emphasized that commercial marijuana operations were not protected by their states' laws.
The document released Thursday said prosecutors "should not consider the size or commercial nature of a marijuana operation alone" as a factor for enforcement.
"I hope the attorney general follows through with the spirit of their memo, but we'll have to see," Gieringer said.
But at least in writing, the Justice Department has now decided against seeking to block new state laws in Colorado and Washington that legalize the recreational use of marijuana.
They also said they will not bring federal prosecutions against dispensaries or businesses that sell small amounts of marijuana to adults.
A department official stressed, however, that marijuana remains illegal under federal law, and that U.S. prosecutors will continue to aggressively enforce the law against those who sell marijuana to minors or to criminal gangs that are involved in drug trafficking.
Atty. Gen. Eric Holder described the Obama administration's middle-ground approach to marijuana enforcement in a call to the governors of the two states.
Under the new guidance, a marijuana dispensary will not be targeted by federal prosecutors based on its size or its volume alone, an official said.
This change could have an immediate effect in states where medical marijuana is legal under state law.
Ethan Nadelmann, executive director of the Drug Policy Alliance, said Thursday's announcement will reverberate not only in Washington and Colorado, but also in California and New York, and in other countries as well.
In a phone interview from Jamaica, Nadelmann said that country is moving to legalize marijuana and that some officials had been expecting opposition from the U.S. But Nadelmann said he told them there was now a lot less to fear.
"With today's announcement, it reinforces what I was saying in a huge way," Nadelmann said. "I was expecting a yellow light, but this light looks a lot more greenish than I had expected."
"The White House is essentially saying proceed with caution," he said.
Nadelmann said the announcement is "significant for the growing number of the other states where the majority of the electorate favor legalizing marijuana and it has international implications" for countries like Jamaica and Uruguay.
As for California, Nadelmann said "there's more or less a consensus among key allies to try and put this on the ballot in 2016."
Times staff writer David Savage contributed to this report.