Our drug prohibition can’t be understood without recalling that it began along with alcohol prohibition.

Why, then, was drug prohibition instituted? And why did it quickly evolve into a fierce and highly punitive set of policies rather than follow the more modest and humane path pursued by the British? In part, the passage of the federal Harrison Narcotic Act, in 1914, and of state and local bans before and after that, reflected a belated response to the recognition that people could easily become addicted to opiates and cocaine. But it also was closely intertwined with the increasingly vigorous efforts of doctors and pharmacists to professionalize their disciplines and to monopolize the public’s access to medicinal drugs. Most of all, though, the institution of drug prohibition reflected the changing nature of the opiate- and cocaine-using population. By 1914 the number of middle-class Americans blithely consuming narcotics had fallen sharply. At the same time, however, opiate and cocaine use had become increasingly popular among the lower classes and racial minorities. The total number of consumers did not approach that of earlier decades, but where popular opinion had once shied from the notion of criminalizing the habits of elderly white women, few such inhibitions impeded it where urban gamblers, prostitutes, and delinquents were concerned.

The first anti-opium laws were passed in California in the 187Os and directed at the Chinese immigrants and their opium dens, in which, it was feared, young white women were being seduced. A generation later reports of rising cocaine use among young black men in the South—who were said to rape white women while under the influence- prompted similar legislation. During the 1930s marijuana prohibitions were directed in good part at Mexican and Chicano workers who had lost their jobs in the Depression. And fifty years later draconian penalties were imposed for the possession of tiny amounts of crack cocaine—a drug associated principally with young Latino and African-Americans.

But more than racist fears was at work during the early years of drug prohibition. In the aftermath of World War I, many Americans, stunned by the triumph of Bolshevism in Russia and fearful of domestic subversion, turned their backs on the liberalizing reforms of the preceding era. In such an atmosphere the very notion of tolerating drug use or maintaining addicts in the clinics that had arisen after 1914 struck most citizens as both immoral and unpatriotic. In 1919 the mayor of New York created the Committee on Public Safety to investigate two ostensibly related problems: revolutionary bombings and heroin use among youth. And in Washington that same year, the Supreme Court effectively foreclosed any possibility of a more humane policy toward drug addicts when it held, in Webb et al. v. U.S. , that doctors could not legally prescribe maintenance supplies of narcotics to addicts.

But perhaps most important, the imposition of drug prohibition cannot be understood without recalling that it occurred almost simultaneously with the advent of alcohol prohibition. Contemporary Americans tend to regard Prohibition as a strange quirk in American history—and drug prohibition as entirely natural and beneficial. Yet the prohibition against alcohol, like that against other drugs, was motivated in no small part by its association with feared and despised ethnic minorities, especially the masses of Eastern and Southern European immigrants.

Why was Prohibition repealed after just thirteen years while drug prohibition has lasted for more than seventy-five? Look at whom each disadvantaged. Alcohol prohibition struck directly at tens of millions of Americans of all ages, including many of society’s most powerful members. Drug prohibition threatened far fewer Americans, and they had relatively little influence in the halls of power. Only the prohibition of marijuana, which some sixty million Americans have violated since 1965, has come close to approximating the Prohibition experience, but marijuana smokers consist mostly of young and relatively powerless Americans. In the final analysis alcohol prohibition was repealed, and opiate, cocaine, and marijuana prohibition retained, not because scientists had concluded that alcohol was the least dangerous of the various psychoactive drugs but because of the prejudices and preferences of most Americans.

There was, of course, one other important reason why Prohibition was repealed when it was. With the country four years into the Depression, Prohibition increasingly appeared not just foolish but costly. Fewer and fewer Americans were keen on paying the rising costs of enforcing its laws, and more and more recalled the substantial tax revenues that the legal alcohol business had generated. The potential analogy to the current recession is unfortunate but apt. During the late 1980s the cost of building and maintaining prisons emerged as the fastest-growing item in many state budgets, while other costs of the war on drugs also rose dramatically. One cannot help wondering how much longer Americans will be eager to foot the bills for all this.

Throughout history the legal and moral status of psychoactive drugs has kept changing. During the seventeenth century the sale and consumption of tobacco were punished by as much as death in much of Europe, Russia, China, and Japan. For centuries many of the same Muslim domains that forbade the sale and consumption of alcohol simultaneously tolerated and even regulated the sale of opium and cannabis.