It all goes back to the Vietnam War, and Nixon trying to crack down on the subculture of hippies that seemed to be the source of much political contest for him.
How comes this affects the rest of the world even heavier than it does the USA then? Weed and shrooms get legalized/decriminzlized all over the States, MDMA and ketamine therapies are available, ADHD patients have their adderall, even opioids are used so widely it has became a serious problem, yet in most of the countries all these are criminalized heavily and carrying even a tiny dose with you aboard a plane is unthinkable.
This is a problem with trade deals. Having a trans-atlantic trade deal between the USA and the EU (so you could just buy stuff from overseas like you do within your home union - without customs clearance and extra taxation) would be amazing but every time such is proposed it comes with a requirement to start a nonsensical war on "Internet piracy".
