Oooohhhh, I just GOTTA jump in here...
Some of you might know me from THR, my nick over there is Trooper (unfortunately that one was already taken over here). I used to be a federal police officer in Germany and work as a part-time English teacher and interpreter now.
First, just like the US, Europe isn't one monolithic homogenous block. While most political parties all over Europe tend to be a bit more state-oriented, there are are major social and political differences between European countries.
Second, Europe has seen elementary changes during the last 100 years. Some countries have literally been destroyed and completely rebuilt more than once in that timeframe. Pointing out that Europeans did more than their share in killings some 60 or 100 years ago will not help us finding out what the criminological differences of today are and why they exist, it's just a case of "Blblblblblb, you did worse than I..."
Third, the fact that most European countries indeed had their left-wing radical terrorist groups (like the Red Army Faction a.k.a. Baader-Meinhoff-Group in Germany, the Action Directe in France, and the Red Brigades in Italy) doesn't really say anything useful about the level of violent street crime in those countries. The terrorist groups in the '70s and '80s were relatively small, targeted only certain key persons and thus didn't really change the average citizen's risk of becoming a crime victim.
I honestly believe your assertions that life in the US ist not really more dangerous than over here if you stay out of the hot spots. But as someone else already mentioned, the same principle applies to Europe. It is common knowledge that most street crime occurs in what one might call "bad neighbourhoods".
So the real question is: are there more and worse ghettos/hot spots/bad neighbourhoods in the US? If yes, why? The murder rate undisputably IS lower over here (I can only speak for Germany, e.g. British circumstances might be different). Konstantin's question why dutch Drug dealers aren't shooting each other up to the extent they do in the states is quite valid IMO.
Once again to all those who might have felt insulted in their patriotism or political beliefs during the previous debate: I don't really want to engage in a "My country is better/safer than your country"-contest. FYI I don't like socialist ideas either, I know lots of things I'd like to change in my country etc.etc. etc.
I'm honestly interested in finding out where the actual reasons for the aforementioned differences lie. I don't really subscribe to Michael Moore's theory that America is simply a violent country with a violent history and population.
Regards,
Trooper