Sure, Nixon seemed largely worried about addiction, and thought that addiction running rampant was harming the country.. his top concern however was not the general population but the military in Vietnam at the time.
His actions also suggest he saw the addicts as mostly victims, this is seen by the fact that he significantly reduced penalties for possession and use. But his goal was still to eliminate the number of addicted people in the USA. So he started the DEA to try and cut the supply off to the users.
In short his tactic was reduced criminality, but increased enforcement, primarily within the military and internationally, but also to reduce the production and supply within the USA.
Most of his actions resulting from the drug policy during his administration were target at the military, enacting things like drug tests and consequences there.