Reassurance

There are now tons of cops, including undercover officers, in London's Underground, part of whose role is to be a reassuring presence. This reminds me of the Monty Python sketch from "The Meaning of Life" in which a man's leg has been bitten off by a tiger, and a doctor comes by to reassure the man. The patient thanks the doctor for reassuring him, the doctor asks if there's anything else he could reassure the patient about, and then the patient asks if his leg will grow back. And then, the moment of truth.