Heeding the advice of Gen. David Petraeus, Barack Obama has committed 17,000 more troops to Afghanistan and will keep 50,000 in Iraq after U.S. combat operations end in August 2010.

But are U.S. vital interests more threatened by what happens in Anbar or Helmand than in the war raging along our southern border?

Prediction: After all U.S. troops in Iraq, Afghanistan and Korea have come home, there will be a U.S. army on the Mexican border. For this is where the fate of our republic will be decided, as the fate of Europe will be decided by the millions streaming north from the Maghreb and Middle East, sub-Sahara and South Asia.

Last year, 6,000 Mexicans died in drug-related killings in a war where the tactics are massacre, murder, kidnapping and beheading.

President Felipe Calderon has ordered another 5,000 troops and 1,000 police to the border. Primary target: Ciudad Juarez, across the Rio Grande from El Paso.

Some 2,500 federal troops are already in Juarez, where in 2008 there were 1,600 drug-related murders. Gun battles occur every day. Nationally, 45,000 army troops and police are committed to this war that Mexico is not winning. For, according to the March 3 Washington Times, the Pentagon now estimates the cartels field more than 100,000 foot soldiers.

The chief of police of Juarez just resigned after a cartel threatened to kill an officer even 48 hours if he did not. To prove its seriousness, the cartel murdered four cops, including the chief’s deputy. Last year, 50 police officers in Juarez were murdered.

“The decision I am taking is one of life over death,” said Chief Roberto Oduna. The chief would seem to have a point. In January, his predecessor’s head was found in an ice cooler outside a police station. The mayor keeps his family in El Paso, as they have been threatened with decapitation.

Friday, the State Department declared, “Corruption throughout Mexico’s public institutions remains a key impediment to curtailing the power of the drug cartels.” Calderon retorts that, while the murders may be committed in Mexico, the cash and guns come from the United States.

With oil revenue down since the price dropped $100 a barrel, and remittances down from Mexican workers in the United States as the U.S. economy tanks, tourism, too, has begun to die. Beheadings in and around Acapulco have not helped. Warnings have been issued to U.S. college kids to avoid Mexico on spring break, as kidnappings for ransom are rampant. Restaurants and bars in Juarez that catered to folks from El Paso and soldiers from Fort Bliss are shutting down.

In February, in the resort town of Cancun, a retired army general sent to create an elite anti-crime unit was kidnapped, tortured and shot. Mexican troops raided Cancun’s police headquarters and arrested the chief and dozens of his officers in connection with the murder.

Add a collapsing global economy to a losing war with drug cartels, and Mexico is at grave risk of becoming a failed state, a narco-state, with a 2,000-mile border with the United States.

How does one win a drug war when millions of Americans who use recreational drugs are financing the cartels bribing, murdering and beheading to win the war and keep self-indulgent Americans supplied with drugs?

There are two sure ways to end this war swiftly: Milton’s way and Mao’s way. Mao Zedong’s communists killed users and suppliers alike, as social parasites. Milton Friedman’s way is to decriminalize drugs and call off the war.

When Richard Nixon declared the War on Drugs in 1972, Milton, writing in Newsweek, objected on ethical grounds:

On ethical grounds, do we have the right to use the machinery of government to prevent an individual from becoming an alcoholic or a drug addict? For children, almost everyone would answer at least a qualified yes. But for responsible adults, I, for one, would answer no. Reason with the potential addict, yes. Tell him the consequences, yes. Pray for and with him, yes. But I believe that we have no right to use force, directly or indirectly, to prevent a fellow man from committing suicide, let alone from drinking alcohol or taking drugs.

“Am I my brother’s keeper?’” asked Milton, answering, “No.”

Americans are never going to adopt the Maoist solution. For the users of drugs are all too often classmates, colleagues, friends, even family. Indeed, our last three presidents did not deny using drugs.

Once, a Christian America outlawed and punished homosexuality, abortion, alcohol, loan-sharking and gambling, all as criminal vice. Now, homosexuality and abortion are constitutional rights. Gambling and booze are a rich source of government revenue. And loan-sharking is done by credit-card companies, and not just the Corleones.

Will we raise the white flag in the drug war, as well?

Which is the greater evil? Legalized narcotics for America’s young or a failed state of 110,000 million on our southern border?

Some choice. Some country we’ve become.