Its abolition has generally been attempted by treaty.  In the treaty of Prussia and the United States, in 1785, stipulations against private armed vessels were included.  In 1675, a similar agreement was made between Sweden and Holland, but the agreement was not performed.  France, soon after the breaking out of the war with Austria, in 1792, passed a decree for the total suppression of privateering, but that was a transitory act, and was soon swept away in the tempest of the Revolution.

[Sidenote:  Piratical Privateering.]

On these considerations naturally follows that of the classes of
Privateers that can be considered Pirates.

A Privateer differs from a Pirate, in that—­first, the former is provided with a Commission, or with Letters of Marque from a Sovran, of which the Pirate is destitute.  Secondly, the Privateer supposes a state of war (or at least that of reprisals); the Pirate plunders in the midst of peace, as well as in war.  Thirdly, the Privateer is obliged to observe the rules and instructions that have been given him, and to attack by virtue of them only the enemy’s ships, or those neutral vessels which carry on an illicit commerce; the Pirate plunders indiscriminately the ships of all nations, without observing even the laws of war.  But in this last point Privateers may become Pirates when they transgress the limits prescribed to them; and this is one of the reasons why we often see the former confounded with the latter.[94]

Under these general definitions, we see that it is quite open to any citizen of the world to become a privateer under a foreign Sovran; and Martens goes on to say, that

“there is nothing that prevents the granting of Letters of Marque, even to the subjects of neutral or allied powers who are able to solicit them; but since it is contrary to neutrality to suffer subjects to contribute by this means to the reinforcement of one of the belligerent powers, and to the annoyance of the other, states generally prohibit their subjects from taking Letters of Marque from a power, without the permission of their Sovereigns, and many treaties oblige them also to prohibit their subjects from doing it, as well as to forbid every species of armaments on the enemy’s account, in their ports.  However, the enemy is not justified in punishing them as pirates, when they have letters patent from one of the powers with whom it is at war, although their ship may be confiscated."[95]

The laws of the United States have made ample provision on this subject, and they may be considered as an expression of the general wish of civilized nations; and they prescribed specific punishment for acts which were before unlawful.

American citizens are prohibited from being concerned, beyond the limits of the United States, in fitting out or otherwise assisting any private vessel of war, to cruize against the subjects of friendly powers.[96]