End the War on Drugs. Invest in harm reduction and rehabilitation centers. Decriminalize individual possession of small quantities of (most) drugs. Unrestrict researchers from performing research on psychedelic compounds.
But then you haven't ended the war on drugs. We need legalization, not decriminalization.
It's inhuman and stupid to put people in prison for selling drugs. In the meantime the US is going to crumble under policies like this, while gangs will become increasingly powerful.