Legal Definitions - letter of marque

A letter of marque is a formal authorization issued by a national government to a private citizen or ship owner, granting them permission to attack and seize the vessels and property of an enemy nation during a time of war or conflict. Essentially, it deputizes private individuals to act on behalf of the state in naval warfare, allowing them to engage in acts that would otherwise be considered piracy, but are sanctioned as legitimate acts of war. In the United States, only Congress holds the constitutional power to issue such letters.

Here are some examples to illustrate the concept:

• During the American Revolutionary War, a wealthy Boston merchant whose shipping fleet was being decimated by British naval blockades might have petitioned the Continental Congress for a letter of marque. If granted, this letter would legally empower him to arm his remaining merchant ships, outfit them with cannons, and then actively seek out and capture British merchant vessels, seizing their cargo and selling it for profit, all while contributing to the American war effort by disrupting enemy supply lines.

  This example demonstrates a private citizen (the merchant) receiving government authorization (the letter of marque) to engage in acts of war (capturing British vessels) against an enemy nation (Great Britain) during a conflict, turning private resources into a tool of national defense and offense.

• Imagine a hypothetical scenario where a small coastal nation is engaged in an undeclared naval conflict with a larger, more powerful neighbor. The smaller nation, lacking a substantial navy, might issue letters of marque to its experienced commercial fishing captains. These letters would legally permit the captains to arm their fishing trawlers and target the larger nation's commercial shipping, seizing their cargo or even the vessels themselves, as a form of economic warfare and retaliation for prior aggressions, without escalating to a full-scale military deployment.

  Here, the letter of marque allows a government with limited military resources to leverage its private citizens and their vessels for strategic purposes (economic warfare and retaliation) against an adversary, legitimizing actions that would otherwise be considered illegal.

• In the early 19th century, during a period of heightened tensions and naval skirmishes between two European powers, a ship owner whose vessel was unjustly seized by the opposing nation's navy might appeal to his own government for a letter of marque. With this official document, he could then legally outfit a new ship and specifically target vessels belonging to the nation that wronged him, aiming to recover losses or inflict similar damage, thereby engaging in authorized "reprisal" rather than mere piracy.

  This illustrates the "reprisal" aspect of a letter of marque, where a private individual is given legal authority by their government to retaliate against an enemy nation for specific grievances, transforming a personal vendetta into a state-sanctioned act of war.