(c) The nationality of the vessel has been sometimes regarded as the sole fact determining liability of goods to capture, and at other times affecting only the vessel itself.
Under the rules of the Consolato, the flag determined the liability of the vessel only. Under the French ordinances, the flag contaminated the goods. From 1778, the doctrine that the neutral flag covered enemy goods became more commonly accepted. This was especially emphasized by the armed neutrality of 1780.
Some of the agreements of the United States will show the variety of practice even in recent times. By Art. XXIII. of the Treaty of 1778 with France it is provided, "that free ships shall also give a freedom to goods, and that everything shall be deemed to be free and exempt which shall be found on board the ships belonging to the subjects of either of the confederates, although the whole lading or any part thereof should appertain to the enemies of either, contraband goods being always excepted." In the Treaty of 1785 with Prussia occurs the following: "free vessels making free goods, insomuch that all things shall be adjudged free which shall be on board any vessel belonging to the neutral party, although such things belong to an enemy of the other." In the Treaty of 1795 with Spain is a similar provision, excepting, however, contraband of war. It is asserted in the Treaty of 1799 with Prussia that as the doctrine of "free ships make free goods" has not been respected "during the two last wars," and in the one "which still continues," the contracting parties propose "after the return of a general peace" to confer with other nations and meantime to observe "the principles and rules of the law of nations generally acknowledged." The Treaty of 1819 with Spain interprets the clause of the Treaty of 1795, in which it is stipulated that the flag shall cover the property, by saying, "that this shall be so understood with respect to those Powers who recognize this principle; but if either of the two contracting parties shall be at war with a third party, and the other neutral, the flag of the neutral shall cover the property of enemies whose Government acknowledges this principle, and not of others." The Treaty of 1794 with Great Britain expressly provides that property of an enemy on a neutral vessel shall be good prize. In 1887 it was agreed in the treaty with Peru "that the stipulation in this article declaring that the flag shall cover the property shall be understood as applying to those nations only who recognize this principle; but if either of the contracting parties shall be at war with a third, and the other shall remain neutral, the flag of the neutral shall cover the property of enemies whose Governments acknowledge this principle, and not that of others."[435] In spite of these variations, the practice of the United States has been much more uniform than that of the states in which the foreign relations have exercised a more direct influence.
(d) Since 1856 the principles enunciated in the Declaration of Paris have generally prevailed. The provisions in regard to the flag and goods are:—
"2. The neutral flag covers enemy's goods, with the exception of contraband of war.
"3. Neutral goods, with the exception of contraband of war, are not liable to capture under the enemy's flag."[436]
This agreement bound only those states which signed it. A few states, including the United States, Spain, Mexico, Venezuela, and China, did not accede to these provisions. The United States declined because the government desired a provision exempting all private property at sea from capture.[437] In the War of 1898, the United States announced that the rules of the Declaration of Paris would be observed, and Spain made a similar announcement except as to the clause in regard to privateering.[438] Spain did not, however, make use of privateers. The goods of a neutral embarked in a belligerent carrying vessel are liable to the damages or destruction which may be the consequence of necessary acts of war. Destruction not the result of such necessary acts would be in violation of the spirit of the Declaration of Paris, and the neutral might justly demand reparation.
The rules of the Declaration of Paris have been so generally accepted in practice that there is little possibility that they will be disregarded by the civilized states of the world.
[§ 131. Contraband]
Contraband is the term applied to those articles which from their usefulness in war a neutral cannot transport without risk of seizure. While a state is under obligation to prevent the fitting out of hostile expeditions and to refrain from furnishing belligerent ships warlike material, a state is not bound to prevent the traffic of its citizens or subjects in contraband of war. Such articles as are contraband may be seized on the high seas,[439] and by the Declaration of Paris are not protected by the neutral flag.[440]
Of the articles of commerce themselves, Grotius makes three general classes:—