The Secretary of the Navy ( Denby ) to the Secretary of State


Sir: By reason of Resolution No. 1, adopted by the United States of America, the British Empire, France, Italy, and Japan at the Conference on the Limitation of Naval Armament and of subparagraphs (a) and (b) thereof which read as follows:

  • “(a) Do existing rules of International Law adequately cover new methods of attack or defense resulting from the introduction or development, since the Hague Conference of 1907, of new agencies of warfare?
  • (b) If not so, what changes in the existing rules ought to be adopted in consequence thereof as a part of the law of nations?”

the General Board was directed to give full consideration to the questions raised in the above quoted subparagraphs.

There are quoted below the results of the General Board’s study of Laws of War as applied to Aircraft:

Proposed Aircraft Rules (Navy Department)

i. definition, nationality, marking

1. An aircraft is a vehicle designed for or capable of the aerial transportation of persons or material. An aircraft permanently assigned to a vessel of war and usually accompanying the vessel may be regarded as a part of the vessel as long as it remains in physical contact therewith.

2. Aircraft may be public aircraft, belonging to or under the control of the state or its officers; or private aircraft, belonging to and under the control of private persons.

3. No aircraft may possess more than one nationality. Every private aircraft shall bear the nationality and registration marks and the name and residence of the owner, in accordance with the laws of its own nation. Every public aircraft shall be unmistakably marked to show nationality and its personnel shall be in uniform and provided with proper papers to prove that they are in the public service. Nationality marks shall be visible from all sides, and shall be so affixed as not to be capable of being replaced by other marks while in flight through the air.

4. The use of the special identification marks of a neutral aircraft by a belligerent aircraft is strictly forbidden and puts the aircraft and its personnel outside the protection of the law.

5. Aircraft and their personnel shall enjoy no immunities incident to employment in hospital or sanitary formations except such immunities as may be mutually agreed upon by the belligerents concerned.

ii. General aerial jurisdiction

6. A state has complete and exclusive jurisdiction in the air space above its territory and above its jurisdictional water.

7. In time of war, any state, neutral or belligerent, may forbid the entrance or regulate the entrance, movement, or sojourn of aircraft within its jurisdiction.

8. Within the immediate vicinity of naval or military operations but outside of neutral jurisdiction a belligerent commanding officer may forbid the passage of aircraft of any kind or prescribe the conditions of entrance.

9. The liability of an aircraft for violation of the laws of war is contingent upon her actual or constructive knowledge of the existence of the war.

10. In time of war, in absence of special stipulations, public aircraft within the jurisdiction of a state are subject to the same regulations as public vessels, and private aircraft are subject to the same regulations as private vessels.

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iii. neutral jurisdiction

11. A neutral may intern belligerent aircraft entering or alighting within its jurisdiction.

12. Belligerent aircraft are bound to respect the rights of neutral powers and to abstain within neutral jurisdiction from all acts which, if knowingly permitted by a neutral power, would constitute a nonfulfilment of its neutrality.

13. A neutral government may intern any aircraft of belligerent nationality and its personnel not conforming to its regulations.

14. The action of a neutral power in using the means at its disposal to prevent the violation of its neutrality by aircraft or to enforce its regulations concerning aircraft is not to be regarded as hostile.

15. A neutral is bound to use the means at its disposal to prevent the fitting out within its jurisdiction of aircraft which it has reason to believe are to be used against either belligerent; and also to prevent the departure of any aircraft intended for such use which has been acquired or fitted out in whole or in part within its jurisdiction. Exportation of parts of an aircraft is not a nonfulfilment of neutrality.

iv. neutral aircraft

16. A neutral public aircraft within belligerent jurisdiction or in the neighborhood of belligerent operations must respect belligerent instructions.

17. A neutral private aircraft found in a belligerent’s own jurisdiction or in the immediate vicinity of naval or military operations, contrary to prohibitions, must obey any order given it by the belligerent. If it does not obey, it is liable to the use of necessary force.

18. A neutral private aircraft entering a belligerent’s jurisdiction, contrary to prohibitions, is liable to confiscation and its personnel to treatment as prisoners of war unless its entrance was due to force majeure or was made in ignorance of the prohibitions.

19. Neutral private aircraft found by a belligerent in the jurisdiction of the enemy may be requisitioned.

20. A neutral private aircraft is liable to capture and condemnation:

if it resists or flees the exercise of belligerent rights;
if its papers are lacking, insufficient or irregular;
if it carries contraband;
if it has engaged, or is engaged, in unneutral service;
if it is within a prohibited war area;
if it is manifestly out of the area justified by its papers.

A neutral private aircraft resisting or attempting to escape after being summoned is subject to the use of necessary force, but should be given an opportunity to land if practicable.

21. Transfer of public or of private aircraft from a belligerent to a neutral to be respected by the opposing belligerent must be:—

Bona fide and unconditional.
Valid under the municipal law of the neutral state in question.
Accomplished prior to the rupture of diplomatic relations and not less than 30 days prior to the outbreak of hostilities between the belligerents concerned.

v. belligerent aircraft

22. Enemy public aircraft are, on and after the outbreak of war, liable to seizure and confiscation.

23. Enemy private aircraft found within the jurisdiction of a belligerent on the outbreak of war are not entitled to days of grace but may be retained or requisitioned.

24. Enemy private aircraft outside of neutral jurisdiction are liable to capture and condemnation.

25. Enemy private aircraft within or in sight of the jurisdiction of an opposing belligerent, within or in sight of the area of operations of an opposing belligerent, or within their own national jurisdiction may be dealt with without warning as aircraft of war.

26. Belligerent aircraft of war, if permitted to leave neutral jurisdiction, may take only such fuel and supplies as will enable them to reach their own country.

vi. personnel of aircraft

27. The personnel of captured, belligerent aircraft, have a right to be treated as prisoners of war.

28. The neutral personnel of a captured neutral aircraft, if not guilty of unneutral acts, shall be released.

29. The personnel of neutral aircraft are guilty of espionage if, acting clandestinely or under false pretenses, they obtain or seek to obtain information within, above or in the immediate vicinity of the civil, naval or military jurisdiction of a belligerent.

30. Acts of the personnel of correctly marked enemy aircraft, public or private, done or performed while in the air are not to be deemed espionage.

31. The personnel of enemy aircraft falsely marked to conceal their enemy character may be treated as spies.

32. If belligerent aircraft are interned by a neutral state, their personnel shall, likewise be interned.

vii. bombardment

33. The bombardment by aircraft of cities, towns, villages, dwellings or buildings is forbidden.

34. The bombardment by aircraft of enemy forces, communication and transportation centers, lines of communication and transportation, military or naval establishments, depots of arms or war material workshops, plants and factories used for the manufacture of war material wherever situated is not prohibited.

35. Injuries to non-combatants and to places excluded by Article 33 from bombardment which is incidental to legitimate bombardment can not be regarded as unlawful, but it shall be the duty of the belligerent conducting a bombardment to exercise due care to confine the injury as much as possible to the objectives not prohibited.

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36. In bombardment by aircraft, all necessary steps must be taken, by the commander, to spare as far as possible buildings dedicated to public worship, art, science, or charitable purposes, historic monuments, hospital ships, hospitals and other places where the sick and wounded are collected, provided they are not at the time used for military purposes. It is the duty of inhabitants to indicate such monuments, edifices, or places by signs visible from above, which shall consist of large rectangular panels divided diagonally into two painted triangular portions, one black and the other white. The use of such marks to indicate other buildings or objects than those specified shall be deemed an act of perfidy.

viii. visit and search

37. Outside of neutral jurisdiction, belligerent aircraft of war have the rights of visit, search and seizure accorded to vessels of war.”

These proposed “Aircraft Rules” meet with the sanction of the Navy Department.


Edwin Denby