Story highlights David Frum: In August, the Obama administration retreated on marijuana policy

Frum: It's important to appreciate that "medical marijuana" is a laughable fiction

He says the emerging marijuana industry will target young people and minorities

Frum: It is a myth that marijuana is harmless and nonaddictive; we need better policy

"We're on the brink of creating Big Marijuana." That warning comes from my friend Kevin Sabet, a former senior adviser on drug control policy under President Barack Obama. Sabet now heads Smart Approaches to Marijuana , an anti-legalization group on whose board I sit.

At the end of August, the administration that Sabet served announced a retreat on marijuana policy. It will allow the states of Washington and Colorado to proceed with the legal retailing of marijuana. And it will get out of the way of the approximately 20 states that allow so-called medical marijuana.

With a referendum on marijuana scheduled in 2014 in Alaska and action likely in coming years in California, Maine, Massachusetts, Nevada and Oregon, half the states in the union may soon allow the sale of marijuana to almost anybody determined to buy it.

To understand where the marijuana debate is going, it's important to appreciate that "medical marijuana" is a laughable fiction. In California, the typical user of so-called medical marijuana is a 32-year-old white man with no life-threatening illness but a long record of substance abuse.

David Frum

Under Colorado's now-superseded medical marijuana regime, only 2% of those prescribed marijuana suffered from cancer, and only 1% from HIV/AIDS. Some 94% cited unspecified "pain" as the justification for their pot prescription. False patients find unscrupulous doctors: in Oregon, only 10 practitioners write the majority of all marijuana prescriptions in the state. When a TV crew visited a marijuana dispensary in Los Angeles last year, they met for five minutes with a man who turned out to be licensed as an acupuncturist and were then handed a prescription signed by a doctor they never met.

Where marijuana is allowed to be sold, somebody will sell it. As Sabet warns, the marijuana industry of the future is already taking form. In March of this year, Fortune magazine devoted its prestigious cover to the Arcview Group , an investor group seeking to capitalize on the emerging marijuana market.

Warren Buffett famously explained the economics of tobacco: "It costs a penny to make. Sell it for a dollar. Plus, it's addictive!" Alcohol conforms to the same ugly logic. Half of all the alcohol consumed in the United States is consumed by underage and excessive drinkers . As one industry observer has bitterly remarked: "Regardless of its public stance, the industry considers underage and excessive drinking to be profit centers that need nurturing, rather than problems that need solving."

Sabet foresees that the emerging marijuana industry will target the same populations as are targeted by the tobacco and alcohol industries -- young people and racial minorities -- and for the same reason: secure and contented people don't tend to be heavy consumers of psychoactive substances.

JUST WATCHED Washington details pot sale rules Replay More Videos ... MUST WATCH Washington details pot sale rules 01:36

JUST WATCHED Feds loosen marijuana enforcement Replay More Videos ... MUST WATCH Feds loosen marijuana enforcement 02:15

JUST WATCHED Free pot handed out in Colorado Replay More Videos ... MUST WATCH Free pot handed out in Colorado 01:26

Sabet has laid out a better vision of an effective national drug control policy in his new book, "Reefer Sanity." Sabet's message eschews punishment in favor of treatment; it replaces condemnation with compassion. But it understands the difference between compassion and credulity. Nobody ever helped a troubled person by accepting lies at face value.

"Reefer Sanity" debunks seven myths about marijuana, beginning with the biggest myth of all: that this drug is harmless and nonaddictive. It's a message that is all the more timely in the face of last week's report by the Department of Health and Human Services that regular marijuana use surged over the half-decade from 2007 to 2012

"Reefer Sanity" is the best explication I've seen of the errors on which the case for marijuana legalization has been built. It's a book that every concerned parent should read -- and that every advocate of legalization should be challenged to answer.