It was less than one year ago when acting U.S. DEA administrator Michelle Leonhart publicly declared that the escalating violence on the U.S./Mexico border should be viewed as a sign of the "success" of America's drug war strategies.

"Our view is that the violence we have been seeing is a signpost of the success our very courageous Mexican counterparts are having," said Michele Leonhart, who was recently nominated by President Obama to be the agency's full time director. "The cartels are acting out like caged animals, because they are caged animals."

Well, if the DEA's chief talking head thought that some 6,300 drug cartel-related murders in 2008 was an indication of progress, one can only imagine that she believes that this weekend's south-of-the-border killing spree - which included the murder of a pregnant U.S. official and members of her family - must be downright victorious.

To rest of us, however, these acts are nothing short of a senseless tragedy - a tragedy made all that much more heart-wrenching because it is U.S. policy that is helping to fuel this violence.

As I wrote last year in the commentary, "How to End Mexico's Deadly Drug War":

Wire-service reports estimate that Mexico's drug lords employ over 100,000 soldiers - approximately as many as the Mexican army - and that the cartels' wealth, intimidation, and influence extend to the highest echelons of law enforcement and government. Where do the cartels get their unprecedented wealth and power? By trafficking in illicit drugs - primarily marijuana - over the border into the United States.

The U.S. Office of National Drug Control Policy ... says that more than 60 percent of the profits reaped by Mexican drug lords are derived from the exportation and sale of cannabis to the American market. ... (By comparison, only about 28 percent of their profits are derived from the distribution of cocaine, and less than 1 percent comes from trafficking methamphetamine.) ... Government officials estimate that approximately half the marijuana consumed in the United States originates from outside its borders, and they have identified Mexico as far and away America's largest pot provider.

If the Obama administration wishes to once and for all reduce this unprecedented wave of Mexican drug-gang violence, then it needs to remove the drug lord's primary source of income - and that's marijuana trafficking.

Despite 70+ years of criminal prohibition in the United States (and countless billions of dollars spent attempting to interdict marijuana at our southern border), America remains the primary destination for Mexican pot. Why? Because like it or not, Americans consume cannabis; in fact, Americans lead the world in their consumption of pot.

According to a 2007 economic assessment, U.S. citizens spend $113 billion dollars annually to consume an estimated 31.1 million pounds of pot. According to the federal government, over 100 million Americans have used marijuana; over one in ten Americans do so regularly. In short, marijuana prohibition is not, and will not, reduce demand. So then it's time to regulate the supply.

It is time to remove the production and distribution of marijuana out of the hands of violent criminal enterprises and into the hands of licensed businesses, and the only way to do that is through legalization.

Or, I suppose, we could just keep on doing what we've been doing.

On Monday I joined Judge Andrew Napolitano on FoxNews.com to discuss how marijuana legalization - not increasing levels of government prohibition - would quell the violence surrounding the trafficking of Mexican marijuana. You can watch the video here.

The Judge ‘gets it;' let's hope that the administration will one day ‘get it' too.