Short answer: Not a damned thing…
5 December, 1933, after only 13 years, Americans came to their senses and ended one of the worst Progressive social experiments tried — the prohibition of alcohol. Attempting to “nudge” people’s behavior by banning a widely used product was a complete disaster.
Prohibition created a wave of organized crime — tax evasion, violence, official corruption — so obviously connected to abolition that even politicians decided they had to end the program. (Mostly because they wanted more tax money…) That prohibition also grew federal power through law enforcement, and created incentives for police and official abuse of power should not be discounted, either.
Since 1970, the “drug war” has created massive organized crime cartels, destroyed civil rights through surveillance, asset forfeiture (legalized theft), and violence toward the people. It has created an entire class of non-violent criminal, as well, and made the “land of the free” the largest prison state in the world. The “terror war” has accelerated and exacerbated these trends, and to what end?
The latest wave of protests about police violence (Eric Garner in New York City) are directly tied to institutional violence that grows to meet criminal violence — just as the early FBI gained prominence by blasting bank robbers and gangsters with Tommy Guns in the mid-1930s. The protestors, as usual, miss the actual point, being stuck in the ideological mire of critical race theory. It’s not race that is at issue. It’s the criminalization of ordinary activity, like selling your own property (in this case “loosies”, single cigarettes), and the overly aggressive response by police habituated to violence by the new Prohibitions — drugs, free speech, gun ownership. Garner wouldn’t have died if he had cooperated with the police, but at what point should free people refuse to cooperate with authorities enforcing intrusive and immoral laws?
You want less criminality? You want less police violence? You need fewer laws governing people’s every action.