Actually I believe the biggest reason could be mundane. As far as I understand most US police officers are working alone. So even one unarmed sucker punch means

Actually I believe the biggest reason could be mundane. As far as I understand most US police officers are working alone. So even one unarmed sucker punch means game over. I would be scared. In Europe police patrol is usually 2 police officers, so there is much less worry, which allows you to deal with the situations more relaxed.