We seem to believe that putting weapons only in the hands of law enforcement makes us safer. On the contrary, it makes our world far more dangerous. It means that we put sole responsibility for our protection into the hands of these individuals. When they can't or won't protect us (such as in the case of Fiona Pilkington) then what recourse is left to us?
When I lived in the states there was much more emphasis placed on the responsibility of the home owner or head of the family to protect himself and his property. Law enforcement was seen as an aid to that end, but not the end itself. The ethos among Americans is that any power given to the state should also be accessible to the individual who finds himslef under that state's governance. By this priciple the people are never at the mercy of the state; rather the state must find amicable ways in which to work with the people. I'm sure the American users here will correct me if I'm wrong.
No one in Britain ever seems to question the fact that our police are routinely armed. They carry batons and pepper spray with the sole purpose of using them as weapons. You may say that these weapons are there for our protection, but who will be the judge of that? It will inevitably be the police officer who ends up using it.
Our jaundiced view of weapons in this country makes our streets less safe, and breeds a culture of fear in which the carrying of a knife creates panic, but the act of driving a car is routine (despite cars being the most commonly used weapon in the world).