Office of the Historian

500.A15A3/1767: Telegram

The Chairman of the American Delegation to the London Naval Conference (Davis) to the Secretary of State

London, February 4, 1936—7 p.m.
[Received February 4—4:25 p.m.]

84. Your 32, February 1, 3 p.m. The question of armed merchant vessels has so many ramifications and brings up so many issues that it is almost impossible to give you a matured opinion at short notice. The following comments are therefore tentative and by no means exhaustive.

I agree that it would be more practicable and effective to deal with the question of armed merchant vessels by international convention than by domestic legislation but doubt whether the prohibition of the use of neutral ports by armed vessels affords a feasible approach or solution. As the use of neutral ports by armed merchantmen is a matter which involves all seacoast states, it is a question that would have to be dealt with by all such states rather than by the naval powers alone. The only possible method of approach as I see it between the naval powers would be an agreement prohibiting the arming of merchant vessels as a corollary to part IV of the London Treaty. Inasmuch as an effective closing of neutral ports to armed [Page 177] vessels by international accord would be tantamount in any case to a prohibition upon the arming of merchant vessels, I do not see that an agreement for the latter would be essentially more difficult to achieve than the former. In fact it might be easier because it would involve only the states possessing merchant marines and would not raise the whole question of the rights and duties of neutrals. The members of the League of Nations certainly would not concur in our conception or definition of neutrality. It is doubtful in fact whether any conception of neutrality can now be discussed without raising the issue of differing types of war, its effect on the interests of various nations and the special status of League powers as regards neutrality.

Moreover, since the prohibition of the arming of merchant vessels in time of war would deal with questions directly related to naval powers and naval armament it could more logically and easily be brought up in the course of the Naval Conference.

A new rule of international law prohibiting the arming of merchantmen could, however, become effective only on certain fundamental conditions.

1.
That all powers possessing: submarines should adhere to the provisions of part IV of the London Treaty.
2.
That the laws of war relating to air attack should be so altered by universal agreement as to prohibit all air attack on merchant vessels.
3.
That the prohibition of the arming of merchant vessels should cease to operate if and when any state should violate the prohibition of submarine or air attack.

With respect to 2 above the new factor of air attack upon merchant vessels is one which may entirely change the primary reasoning for arming of merchant vessels and require a complete revision of the earlier concepts of international law relating to attack upon merchant vessels. It seems very doubtful whether any agreement relating to merchant vessels can be concluded without dealing with the laws of war covering bombardment from the air. I think it most unlikely that any power would agree to forego the possibility of antiaircraft defense on merchant ships when, for example, air attack constitutes such an effective retaliation against blockade.

In my opinion it will in any case be exceedingly difficult to get all the maritime states to abandon what has in the course of time come to be considered as an immemorial and inherent right of merchantmen to arm themselves for self-defense. I fear in particular that the British reaction to any such proposal would be unfavorable although if we were to suggest to them the conclusion of an agreement to prohibit the bombarding of merchant ships from the air as a prerequisite to an agreement to prohibit the arming of merchant vessels it might [Page 178] induce them to consider favorably acceptance of the latter proposal. If you wish me to do so I might informally sound the British out as to the general idea of a revision of the laws of war along the lines of a simultaneous and concurrent protest against submarine and air attack on merchant vessels and of the arming of merchant vessels.

Davis