The U.S. government contain two different methods to deal along with illegal drug use. Firstly, the government has tried a "war on drugs", along with the idea of keeping illegal drugs out of the country. Secondly, the "Just say no" campaign has been utilized to make individuals more aware of the harmful effect of drugs. Employ supply and demand to analyze the effect of these two separate policies.
The "war on drugs" leads to a decreased supply of drugs. The decrease in supply pushes the equilibrium price up & the equilibrium quantity down. The "Just say no" campaign is designed to decrease the demand for drugs. It will lower both the equilibrium price & quantity.