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.
Legalization of drugs should happen and will eventually happen. Do you think an addict should be imprisoned if they find the source of his addiction in his possession? Why don't they arrest drunkards then for carrying a bottle of vodka? Addiction is a sickness and addicts should be offered help not punished. Also, if someone wants to waste himself in his home it's his choice and he should have the right to do so.
As for smoking, you might regret it but some other people may find it a part of their lives.