http://www2.potsdam.edu/hansondj/LegalDrinkingAge.html
Most Westernized countries have set their legal age at 18 years old to to purchase alcohol. The American legislation caused the consumption of alcohol to become a vice and a hazard rather than a social gathering.
College students learn to binge drink instead of finding their comfortable limit because of the raised age.
If you are old enough to pay taxes, vote, and die for your country you are old enough to buy a beer to go with dinner.