Something I've noticed is that the American police are growing increasingly estranged from the populace. Both police and civilians have a strong "us vs them" mentality. There seems to be a sense among both of them that the other party is out to get them.
There also seems to be a sense that this is the natural way of things, although I could be wrong here.
With a few exceptions, this is how I've always felt with the local police around here. I've never had a pleasant run-in with the police except for a couple of occasions when they came to my elementary school and did an anti-drug thing, in that case it was obviously PR and obviously trying to make themselves seem nice around the kids.
Even the few times I've needed their help with something, I came away feeling like I had done something wrong (even though I hadn't, other than simply asked them to do their jobs.) I'm not saying they're all like this, I have known a few that are nice, at least once you get to know them, but outside of a personal relationship with them, like I said, nothing but bad feelings.
On my visit to Europe though, things were completely different. Now, I wasn't there long enough, nor had enough contact with the police over there to make a informed opinion, but the couple of times i had to deal with them, and then adding in the security at their airports, I never felt scared, or worried or even bothered by their presence. They were there doing their jobs, and part of me even felt a slight relief at it. There was a bit of annoyance at the traffic laws (especially the speeding cameras in some areas) but I never felt like the police there were a threat or bullies. Forgive me if my opinion is completely off, but it was just something I noticed. I also noticed this, although to a lesser extent in Mexico, and the police there carried SMGs on their hips. Somehow their demeanor didn't make that seem like anything to be worried about though. Somehow that submachine gun worried me less than the tazers our police carry. Silly, maybe, stupid, quite possibly, but that's just how I felt, and for me, the feeling I get from having those sorts of officials around is one of the more important things to me. I'd much rather feel reassurance than fear and paranoia. But again, maybe I was just too ignorant about those areas, and too knowledgable about my own to feel the right emotions in the places I wasn't familiar with.