"It is now apparently part of the normal doctrine of those who advocate this system that no distinction can be made between combatants and non-combatants, and that a perfectly legitimate and indeed necessary method of warfare will be the wholesale destruction of unfortified cities and their inhabitants. No doubt there will be countervailing efforts to prevent such things happening; but there is, at any rate, one section of military thought which believes that the only way to stop the bombardment of the cities belonging to one belligerent will be the bombardment of the cities belonging to the other."