I think this may be an unfair metaphor, because we have a police force and laws that give us incentive to not murder our neighbours in their sleep and give us a

I think this may be an unfair metaphor, because we have a police force and laws that give us incentive to not murder our neighbours in their sleep and give us assurance that we will be protected while we sleep ourselves. On the world scale, this doesn't exist. If there was no laws, police, or government and a serial murderer moves in beside you, you may very well try to murder him in his sleep.