YES, but not the way you meant it. At point blank range my Glock 24, pointed directly into a perpetrator's face was a more than compelling reason to stop an imminent attack.
Like a previous poster stated, the presence of a firearm, even in the holster, has a chilling effect on persons with ill intent. There is no way of knowing how often my service weapon has detered an ill-conceived idea of someone who may have otherwise furthered his intentions.
VH