Hi!
When I was a minor we had no drinking laws. OTOH, you could only get a driver's license at 18 years old. We have some drinking laws in effect now - minors under 18 shouldn't be able to get a drink, but that's only cosmetic, and in practice you can go to a night club (if they let you in) and drink yourself to death.
We have the mentioned 'wine culture', only those who think it consists of a glass or two after the meal are mistaken. That's a snob's wine culture. The real wine culture involves drinking quite a lot of wine, usually in a wine cellar at your neighbour or a friend.
See, we are a very small country(2 million), but we have more than 10.000 wine cellars, and possibly even much more. In regions where grapes grow, almost everybody has a small piece of land and makes own wine. It's like a national sport.
We have a lot of alchoholics (we're in the top five in the world I believe with Ireland just behind us..
), but I believe this problem kicks in at middle age. Our minors are cool, and usually have a period of heavy drinking in their life, but that's allright.
When I was a minor, not only we didn't have a licence, we didn't have a car and no parent would borrow a car to a minor, most not even to an older child. Some had small motorcycles though.
In cities, we could use public transport, and in villages just walk or use motorcycles.
We have problems with car accidents, but this relates to many other factors - very fast cars, small and winding roads, and driving culture.
We have a problem with the 'western culture' coming to us. Guns, drugs, gangs,crime - when I was a minor I could be left aqlone to wander the streets of our capital city, totally drunk, in the middle of the night, and there was really no danger. Girls could do it. I've done it regularly to get home after 'a social event'. Nowadays it's becoming more dangerous because of the mentioned problems. It's still quite safe here - much more so than in any other European capital - and it's a small place (400k people).
The point is, everything is interconnected. In US, looks like minors have to use cars to socialize, and they shouldn't drink because of that. Also, they have access to guns, and shouldn't drink because of that. They don't enjoy a wine culture society to learn to drink in a family environment, and that's a minus too.
In the end, we have more alchoholics, more car accidents, more suicides and much much less crime and shootings. Probably this relates to other factors.
When I was a minor, I drank and I smoked. Now I don't do either, but I have a glass of wine now and then with a meal or without. My alco consumption went from two liters of wine per week to one glass per week. And this is typical for middle class city folks around here. Then there are lots of people whose only sunshine is drinking, as they see it, and it relates to social problems, not to their history of drinking as minors - I know some personally.