The “war on drugs” introduced money and organised crime into drug use. Money turbo charges addiction by motivating dealers to addict people. Almost unlimited money becomes available. Addicts queue up to become dealers. A black economy with sophisticated infrastructure grows around each drug.
These underground economies have expanded to into mainstream political and economic life. All levels of law enforcement, banking and politics are directly and indirectly corrupted. While one arm of government creates scarcity by legislating and policing prohibition, another is involved in the harvest and distribution of profits.
Drug and arms dealing link up because large scale production requires protection. Drug dealers form alternative governments, take over or corrupt existing governments or both. Competing players are capable of sending governments to war. Wars have been fought in Vietnam, Middle and South America and Afghanistan partly for control of the billions of black market dollars from the illegal drug trade.
Many drugs like heroin eliminate pain and dampen emotions leaving users less aware of the feelings of others. Amphetamines promote rage and violence. Social niceties vanish. Drug dealers are exploitative and can be violent and sadistic, especially organised militias.
While drug use remains criminalised, armies, politicians, governments, officials and entrepreneurs will continue to be addicted to the excitement of easy money and streets will unsafe.
Since Portugal decriminalised the personal use and possession of drugs, including heroin and cocaine in 2001, drug-related problems, including transmission of diseases, deaths from overdoses and crime decreased while drug use did not go up.