The U.S. federal government spent nearly $18 billion in its effort to fight drugs in 1999, up from $16 billion in 1998. This money, combined with billions more at the state and local levels, was earmarked for a wide range of programs, including education and prevention, drug treatment, the arrest and conviction of drug dealers and users, and the interdiction of drugs at the nation’s borders. This massive antidrug campaign—particularly the law enforcement component of it—is commonly referred to as the “war on drugs.”

Critics contend that the war on drugs is a failure and a waste of taxpayers’ money. They point out that despite massive spending and aggressive police tactics, drugs remain plentiful on the nation’s streets and in the schools. Teen drug use has gone up in...