I think that those European countries, because they have more restrictive gun laws and a longer history of subservience to authority, see the sidearm of the police officer as more a badge of authority than a defensive weapon.

England, for example, was proud that their Bobbies went unarmed - no gun at all!  Recent increases in violence and terrorism have changed that to a degree, of course, but I think that's the key - a history of being subjects to authority.  I could be wrong, of course.

Stu