Secondly, their weapons may be unloaded, but they certainly move around in a ready to fire look, sometimes with hands on the trigger.

It doesn't prevent anything, but is certainly efficient in making those who want to feel 'secure' (although it doesn't make them any more secure) better ; and in getting the general population used to seeing soldiers in the street (which is a bad thing).

Auferre, trucidare, rapere, falsis nominibus imperium; atque, ubi solitudinem faciunt, pacem appellant.