I would argue that the war on drugs has not been making any headway and really cannot make any real headway so long as it is being prosecuted in the way that it is.
The war on drugs today is fought mainly by trying to decrease the supply of drugs that enters the US or is sold in the US. However, experience (both with the war on drugs and with Prohibition) seems to tell us that wherever there is demand, there will be supply. It seems to me that the best way to attack drugs would be on the demand side.
Even with all the effort that has been put into stopping drugs, people still have no problem getting their hands on drugs. Even high school students in tiny towns like the one in which I teach can get drugs. If this is how things are after all these years, I do not think headway has been made.