Since September 11, 2001, much attention has been paid to the threats to liberty and equality occasioned by the "war on terror." But precisely because they are unexceptional, the threats created by the "war on drugs" may well be more significant and long-lasting.

The cost of the drug war can be measured in many ways: lives lost, futures ruined, crimes produced, or state and federal resources wasted in a near-futile effort to stanch the flow of drugs into and through the United States.

But these traditional measurements do not tell the whole story. One cost that is more difficult to quantify but no less significant is the effect on our civil liberties. Since the 1970s the Supreme Court has consistently eased the tension between constitutional rights protections and the mandate to enforce the drug laws by diminishing the protections—often in ways that have a disproportionate impact on members of minority groups. In short, the drug war has been waged not only on drug traffickers and users but on liberty and equality.

In cases involving searches for drugs, the Court has created exception after exception to the general rule that searches and seizures must be preceded by probable cause and a warrant. It has upheld the right of the police to ask for "consent" to a search without any articulable basis for suspicion, and without informing the individual that he has a right to say no. It has approved the use of "bus sweeps," in which police approach people in remote areas on long-distance bus rides to increase the likelihood that they will obtain such consent, again without any objective basis for suspicion. And it has permitted the police to stop motorists on the pretext of a traffic violation to search for drugs, again without any individualized basis for suspicion. Together, these rulings cleared the way for the phenomenon known as "driving while black," in which officers freed of any requirement to provide grounds for suspicion use traffic stops disproportionately against black drivers on the unspoken assumption that because they are black, they are more likely to be carrying drugs.

In other drug cases, the Court has watered down the constitutional requirements for "probable cause" that govern the issuance of search warrants in the first place. It has held that the exclusionary rule, which ordinarily bars the use of illegally obtained evidence at trial, does not apply where magistrates issue warrants without probable cause, or where police violate the constitutional requirement that they knock and announce themselves before executing a search warrant on a home. The Court has also approved suspicionless drug testing of student athletes and debaters, and permitted the police to engage in illegal conduct in order to "encourage" a suspect to commit a drug crime in their presence.

The list could go on. And this is no coincidence. Drug laws are especially challenging to enforce. Police cannot rely on victim reports and identifications, as there are no "victims," or at least no victims with an incentive to come forward. And because a car or person carrying drugs does not look different from a car or person carrying anything else, developing the suspicion required for a search or arrest is often difficult. So the Court has watered down the requirements to enable enforcement.

The effects on our liberties are not limited to drug cases. Unlike measures undertaken in the "war on terror," drug enforcement tactics cannot be justified by citing exceptional circumstances or invoking the laws of war. As a result, decisions diluting rights in the name of drug law enforcement undermine protections across the board. Consent searches, pretextual traffic stops and the like can be used for any enforcement agenda; and illegally obtained evidence can be used in drug and nondrug cases alike.

In assessing whether the costs of the drug war exceed its benefits, then, we must pay attention to the ways it has fundamentally altered some of our nation’s most basic commitments. And as technology becomes more sophisticated, the temptation to take shortcuts on rights in the name of identifying drug law violators will press even more insistently on the values we hold most dear. It would be a tragedy if we were to win the battle with drugs only to lose the war over our most fundamental values. But when one realizes that the battle with drugs is unwinnable, our policy begins to look as much like farce as tragedy.

Fighting to restore lost liberties is essential, as the Center for Constitutional Rights and the ACLU are doing in pending lawsuits challenging "stop and frisk" practices in New York and Philadelphia, respectively. But if we are to have any hope of advancing liberty and equality in the long run, we must also focus on decriminalizing our approach to drug abuse.

Read more from the special forum on drug policy reform:

Ethan Nadelmann, "Breaking the Taboo"   Marc Mauer, "Beyond the Fair Sentencing Act"   Bruce Western, "Decriminalizing Poverty"   Tracy Velázquez, "The Verdict on Drug Courts"   Laura Carlsen, "A New Model for Mexico"