Are you, by any chance, looking for absolute safety? It tends to be very expensive to achieve and even then fails often enough.

I hope not. Because Richard's proposal doesn't provide that. Especially when 'drone strikes' have already been brought up in conversation. Sure, most of the remaining risks would sound about as realistic as a plot from a season of 24 but as you say this is a threat well below general background risk level so implausibility is expected.