A lot of vehicles meet both US and European standards for safety out of the factory now. It was was my understanding that there are two versions due to fuel economy restrictions (and fuel type differences).
There are several small differences. I can't find an exhaustive list, but windshield material, bumper height, headlights, and taillights are some that come to mind immediately. Yes, it's the same platform, but the vehicles are "tweaked" for each market safety regulation.
It's not that US is "safer" than EU or vice-versa, it's that the standards are different.
