Hangover stuff aside, American beer is actually has a huge variance in stength. Most people are familiar with the Macro-brews (like Bud, Miller, Coors), but Microbrews can range anywhere from 3.5% up to 20%.
You can say that about almost any country though. When people think of Scottish beer they will think of Tennants (bloody awful, and weak to boot) or some random large brewery owned ales (again, weak and horrible). However I know many a brewery in Scotland that makes lovely beer, and strong beer as well.
When we are defining a countries beer where do we start and stop? Do we classify it by the big names that are available in other countries, or by every micro-brewery? I think beer is too hard to classify, but if you are wanting to pay someone to travel the world sampling every beer in the world to classify countries...then I will volunteer :D