If drugs are legalized will drug usage increase or decrease?
Drug usage is increasing anyway, despite strong drug laws in most countries. With legalisation, the one thing sure to decrease is the huge profit that organised criminals are making from smuggling and sale, and the collateral crime of addicts robbing people and their homes in order to pay an extortionate price, for an intrinsically cheap product, to the mafia.
The state pays for rebabilitation anyway - why not get some of the money back through tax revenue. Not to mention the huge costs of carrying out the failed 'war on drugs'.
After all, alcohol and nicotine are extremely dangerous drugs, but nobody suggests driving them underground and thereby depriving the government of excise duty and at the same time enriching criminals.
If you don't approve of legalisation, you therefore support throwing ever larger amounts of public money into trying to stop something that experience has shown cannot be stopped.