In an ideal world—a laissez-faire free market—seperation of State & Drugs, like we have a seperation of State & Religion. 

However, in the world today, begin with decriminalizion of all drugs & the process of legalizing regulated sessions by licensed practitioners. Then, begin the process of legalizing regulated retail sales. 

The idea is to begin slowly lifting drug laws & regulations in a gradual & linear fashion until there are very little to none. The reason for a slow & linear fashion is so new markets open up to fill the demand for new issues that arise such as third party testing markets.