A different view seems to be taken in the German _Kriegsbrauch_, p.22.One also asks: Under what circumstances does a place, _prima facie_, "undefended," cease to possess that character?
Doubtless so soon as access to it is forcibly denied to the land forces of the enemy; hardly, to borrow an illustration from Colonel Jackson's letter of Thursday last, should the place merely decline to submit to the dictation of two men in an aeroplane.
I read with great pleasure the colonel's warning, addressed to the United Service Institution, and am as little desirous as he is that London should rely for protection upon The Hague article, ambiguous as I have confessed it to be; trusting, indeed, that our capital may be enabled so to act at once in case of danger as wholly to forfeit such claim as it may in ordinary times possess to be considered an "undefended" town.

Let the principle involved in Art.

25 be carried into much further detail, should that be found feasible, but, in the meantime, let us not for a moment relax our preparation of vertical firing guns and defensive aeroplanes.
I am, Sir, your obedient servant, T.E.HOLLAND.
Oxford, May 2 (1914).
The war of 1914 has definitely established the employment of aircraft for hostile purposes, and, as evidenced by the reception given by belligerents to neutral protests, the sovereignty of a state over its superincumbent air-spaces.
On the bombardment of undefended places, _cf.

supra_, pp.

30, 62, 67, 68; _infra_, pp.