The government should just accept the fact that the drugs can't be eliminated. As long as the demand exists, the people will find a way to secure them. The only viable option is to legalize and regulate them.
I am against the legalization of drugs. More than that I don't agree with you that it is impossible to defeat drugs. In order to buy drugs addicts should know where you can buy them. Once they know that might know and the police. The power just didn't really want to deal with this problem.