There is a lot of argument on the necessity of the drug war. The benefits would be revenue gained from taxation, less drug dealers and less drug war associated crime, less money spent on fighting the drug war (police, jails, customs, etc.), easier access to treatment, and of course freedom.
The harmful effects are less clear… will people use more drugs? Will this lead to higher violent drug user crime? Will children have more or less access to drugs?
Well, Portugal legalized all illegal drugs, and so provides a fantastic case study of the issue. In short, the answer is that legalization is better in every possible way (that I can think of at least).
http://www.time.com/time/health/article/0,8599,1893946,00.html?ref=nf
