legalizing it would only intensify the drug battle over other narcotics
I don't see how it would. When it comes down to it, drug traffickers are in it for the money. They may have more flexible values, but if there's more money to be made elsewhere, they're out of there. The truth is if there's no profit to be made illegally; the people will disappear.
Personally, I agree with Bob. Legalize marijuana, and see where that goes. I feel like this is something we might see within the decade on a state level.
However, I also do feel drug possession should be decriminalized. Mostly because I feel it's an unnecessary burden on the prison system. Locking up addicts of any sort just seems like a waste of time. However, if you find someone behind the wheel, I'll gladly support harsh criminal penalties.