The "Geneva Convention" mentioned in the address has, of course, no bearing upon aerial dangers. The answer to the question is contained in the, now generally ratified, Hague Convention No. iv. of 1907. Art. 25 of the regulations annexed to this Convention runs as follows:
"It is forbidden to attack or to bombard by any means whatever (par quelque moyen que ce soit) towns, villages, habitations, or buildings which are not defended."
It clearly appears from the "Actes de la Conférence," e.g. T. i., pp. 106, 109, that the words which I have italicised were inserted in the article, deliberately and after considerable discussion, in order to render illegal any attack from the air upon undefended localities; among which I conceive that London would unquestionably be included.
I cannot venture to ask the hospitality of your columns for an adequate discussion of the gallant officer's second question, as to the binding force attributable to international law. Upon this I may, however, perhaps venture to refer him to some brief remarks, addressed to you a good many years ago, and now to be found at pp. 101 and 105 of the new edition of my "Letters to The Times upon War and Neutrality (1881-1918)."
I am, Sir, your obedient servant,
T. E. HOLLAND
Oxford, April 24 (1914).
ATTACK FROM THE AIR
THE RULES OF INTERNATIONAL LAW
Sir,—In reply to Colonel Jackson's inquiry as to any rule of international law bearing upon aerial attack upon London, I referred him to the, now generally accepted, prohibition of the "bombardment, by any means whatever, of towns, &c., which are not defended." This rule has [068]been growing into its present form ever since the Brussels Conference of 1874. The words italicised were added to it in 1907, to show that it applies to the action of aéronefs as well as to that of land batteries. It clearly prohibits any wanton bombardment, undertaken with no distinctly military object in view, and the prohibition is much more sweeping, for reasons not far to seek, than that imposed by Convention No. ix. of 1907 upon the treatment of coast towns by hostile fleets.
So far good; but further questions arise, as to which no diplomatically authoritative answers are as yet available; and I, for one, am not wise above that which is written. One asks, for instance, what places are prima facie "undefended." Can a "great centre of population" claim this character, although it contains barracks, stores, and bodies of troops? For the affirmative I can vouch only the authority of the Institut de Droit International, which in 1896, in the course of the discussion of a draft prepared by General Den Beer Pourtugael and myself, adopted a statement to that effect. 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.