If the large cigarette companies realized that they had the entire infrastructure set up for the production, packaging, and distribution of marijuana, and diverted advertising and legal costs and man-hours to lobbying the government for legal pot, how long do you think it would take for even the most conservative government to legalize pot? I'd be willing to bet a lot of money that it'd be legal within a year of the lobbying starting.
Guys, the war against pot really isn't, and in fact really never has been, about the right or wrong of smoking it, or even the health repercussions. If those were truly the issues behind the matter, alcohol and tobacco would have been made illegal far sooner than marijuana.
It started as a big business deal between corrupt government and the paper and synthetic fabric industries (specifically Hearst and DuPont), and is now a combination of business with alcohol, tobacco, and large pharmaceuticals, as well as simply not having to admit that the government has been wrong the whole time.
Jmrentis, sheer addiction cannot possibly account for the change in the type of people drinking during prohibition. It wasn't just that the alcoholics kept drinking; the amount of the population who drank (in public, anyway) increased dramatically, and women started to drink much more openly. It wasn't that everyone was addicted so much as it was that drinking was the cool, daring thing to do-- precisely because it was illegal.
I'm not saying that decriminalizing pot will cause the number of pot-smokers to decrease; it will simply shift the total number of smokers to a much more responsible crowd that does it for reasons other than simply breaking the law.
PS-- Oh, and don't get me started on hemp. That plant alone could do wonders to improve the environment singlehandedly, as well as actually improve the quality of quite a few products now in production. For everything you've ever wanted to know on the subject, read Jack Herer's The Emperor Wears No Clothes. Also, for an informative and -very- interesting read, check out Reefer Madness: A History of Marijuana in America by Larry Sloman, which chronicles the history of marijuana from its most ancient days through its introduction in America around 1900 all the way into the pro-legalization movements of the late 1970's.
PPS-- Also, if anyone is interested, I just finished a 5-page term paper for AP US History on the story behind how marijuana was outlawed (including citations, footnotes, and sources for those of you who believe such a paper must be untrustworthy and skewed); if anyone interested in reading it (and knows where to host it), I'd be glad to put it up.