How are we to win our national struggle with cocaine, heroin, marijuana, and other illegal drugs? Everyone agrees that drug-related problems are a plague on our society, destroying lives, helping wreck neighborhoods, poisoning schools, feeding crime, bleeding the economy. Lately, strong voices are saying that the war against drugs as we are now fighting it cannot be won, that the best solution is legalization, or at least decriminalization. What does history, with its case studies of past substance-bans and attempts at regulation and decontrol, tell us might happen if drugs were no longer outlawed? Could we close the criminal marketplace? Make drugs safer for those who use them? Reduce demand? Cut enforcement costs and raise tax revenues? Or would things get worse? Two scholars, Ethan A. Nadelmann of Princeton University and David T. Courtwright of the University of North Florida, have studied the historical record closely. Their answers could hardly be more different.