I really hope Sessions takes him up on the offer. The main difference is that in places like Switzerland and the Netherlands they view drug addition as a _health issue_ rather than a crime you should be locked up for. I think the attitude towards drugs in the US is slowly moving away from Richard Nixon's "war on drugs", and more towards actually helping people with drug problems.
Having said that, Europe is way ahead of the US in a lot of (social) aspects, drugs being one of them.
Nixon and his associates did a lot of damage in this area:
"You understand what I'm saying? We knew we couldn't make it illegal to be either against the war or black, but by getting the public to associate the hippies with marijuana and blacks with heroin. And then criminalizing both heavily, we could disrupt those communities," [former Nixon domestic policy chief John Ehrlichman] said. "We could arrest their leaders. raid their homes, break up their meetings, and vilify them night after night on the evening news. Did we know we were lying about the drugs? Of course we did."
I'm glad Rick Steves made an effort to call out that particular aspect: "And we’re no longer arresting about 8,000 (mostly poor and black) people each year."
Classic example of a law just to make criminals out of otherwise law-abiding citizens. Marijuana law is such a textbook example of everything bad about government. We needed a constitutional amendment to allow the government regulate alcohol, but now you don't even Congress to regulate drugs, you just need the executive. And it can be illegal at the federal level, legal at the state level, illegal at the local level, but not "enforced", so the TSA can get you charged with a felony because you're transporting your small amount of no-THC pain balm across state lines. What a mess we've built ourselves.
Having said that, Europe is way ahead of the US in a lot of (social) aspects, drugs being one of them.