ors, the
United States Government has not yet reached the conclusion that they
are improperly included in a list of contraband. Military operations
today are largely a question of motive power through mechanical
devices. It is therefore difficult to argue successfully against the
inclusion of petroleum among the articles of contraband. As to the
detention of cargoes of petroleum going to neutral countries, this
Government has, thus far, successfully obtained the release in every
case of detention or seizure which has been brought to its attention.

Great Britain and France have placed rubber on the absolute contraband
list, and leather on the conditional contraband list. Rubber is
extensively used in the manufacture and operation of motors, and, like
petrol, is regarded by some authorities as essential to motive power
today. Leather is even more widely used in cavalry and infantry
equipment. It is understood that both rubber and leather, together
with wool, have been embargoed by most of the belligerent countries.
It will be recalled that the United States has in the past exercised
the right of embargo upon exports of any commodity which might aid the
enemy's cause.

_(9) The United States has not interfered with the sale to Great
Britain and her allies of arms, ammunition, horses, uniforms, and
other munitions of war, although such sales prolong the conflict._

There is no power in the Executive to prevent the sale of ammunition
to the belligerents. The duty of a neutral to restrict trade in
munitions of war has never been imposed by international law or by
municipal statute. It has never been the policy of this Government to
prevent the shipment of arms or ammunition into belligerent territory,
except in the case of neighboring American republics, and then only
when civil strife prevailed. Even to this extent the belligerents in
the present conflict, when they were neutrals, have never, so far as
the records disclose, limited the sale of munitions of war. It is only
necessary to point to the enormous quantities of arms and ammunition
furnished by manufacturers in Germany to the belligerents in the
Russo-Japanese war, and in the recent Balkan wars, to establish the
general recognition of the propriety of the trade by a neutral nation.

It may be added that on the 15th of December last, the German
Ambassador, by direction of his Government, presented a copy of a
memorandum of the Imperial German Government which, am