I just gave a speech today on the legalization of marijuana. Speech didn't go to well since I didn't practice much before presenting it, but my outline was rather good.
Anyways, my (American) view on the matter(afterall, I was presenting my argument to a class of Americans. I wasn't researching marijuana legalization on a global scale):
Harry Anslinger had a vendetta against all drugs due to his childhood in which many of her neighbors and family members were addicted to opium/morphine. He was also a racist. For this reason it is not at all surprising that Anslinger's podium for trying to ban marijuana was centered around racism, prejudice, and his irrational and completely unfounded demonization of the drug.
Anslinger got the Marijuana Tax Act of 1937 passed and this was the beginning of the end for marijuana. Anslinger's tax act had unintended consequences, however, since it also ruined the Hemp industry and made medicinal uses for marijuana fade away for a time. It is only recently that some states have finally started to allow marijuana be used for medicinal uses once more.
I would suggest checking out the site:
http://www.drugpolicy.org/marijuana/factsmyths/ to see some of the popular marijuana myths debunked. Only myth they try to debunk on that site I have issue with is the one about using marijuana while pregnant. I would never advocate anyone use marijuana while pregnant.
What amuses me is that a drug that was done away with for obviously racial and prejudicial reasons(and no scientific or societal reasons at all, except for those steeped in prejudice) is still banned today. What is also amusing is that marijuana is safer than alcohol and actual provides proven medicinal value, yet people are unwilling to legalize it.
People say marijuana should stay illegal because it would cause society to deteriorate if it was legalized, but it is the exact opposite. Society deteriorates because it is illegal. In every country where marijuana is legalized or where marijuana laws are lax crime rate is lower. In countries such as the Netherlands, illegal use of marijuana amongst teens even DECREASES once marijuana is legalized. It doesn't increase like people assume it would.
Marijuana legalization would also stimulate the economy. not only through a marijuana market, but through the re-introduction of a hemp industry. Hemp was always a big source of economic benefit in the US from its start. George Washington even promoted the production of hemp, saying "Make the most you can of the Indian Hemp seed and sow it everywhere."
Besides promoting economy, there is the issue of problems created due to the illegality of marijuana. The 1st, 4th, 5th, 6th, and 8th amendment are violated due to the illegality of marijuana. One good example of this is civil asset forfeiture.
