Piracy, a scourge that had been stamped out in the 19th century, still flourishes in those Hobbesian areas of the world where order and the “rule of law” do not exist. The seizure of a U.S.-flagged vessel, the MaerskAlabama, earlier this month and the subsequent rescue of the ship’s captain by the U.S. Navy has alerted Americans to the fact that Somalia and its coast is such an area. Ever since the collapse of the Somali government in 1991, it has been a particularly stark example of what is now called a “failed state.”

According to statistics provided by the International Maritime Bureau, there were 293 incidents of piracy or armed robbery in 2008, of which 130 occurred off the coast of Somalia and in the nearby Gulf of Aden. Of these, about 50 were successful. With the exception of the United States (in the Maersk Alabama incident) and the French, most governments, shipping companies, and insurers have opted to pay ransoms amounting to millions of dollars to free crews and vessels.

What is to be done? One school of thought argues that we should do little or nothing because the cost of stamping out piracy again is too high. They point out that some 21,000 ships transit the Gulf of Aden every year and maintain that 50 successful pirate attacks doesn’t really constitute much of a threat, certainly not one worth expending the resources necessary to eliminate it. Ideas on how we might do so include arming crews or providing specialized armed detachments. As Derek Reveron, my Naval War College colleague, observes, the costs of providing security teams aboard merchant vessels or arming crews and training them to defend the ship probably exceed the costs of paying ransom for the rare ship taken.

In addition, Reveron argues, piracy in this part of the world isn’t an American problem. He contends that piracy is an annoyance, but other than offending our sense of freedom of the seas, it doesn’t for the most part affect American shipping. Thus focusing on piracy is an example of the tail wagging the strategic dog. He argues that the Europeans and Asians, who are quick to demand U.S. leadership on the one hand and criticize the United States for its actions on the other, ought to be responsible for dealing with pirates here.

But others point out that piracy is a threat to a peaceful, commercial “liberal world order.” For instance, the threat of piracy has a dampening effect on commerce, raising insurance rates and other costs of transporting goods by sea. Such increases in the cost of commerce are not good any time, but especially during a recession.

Experience seems to indicate that a “liberal world order” does not arise spontaneously as the result of some global “invisible hand” but requires the actions of a powerful state willing and able to provide the world with the “collective goods” of economic stability and international security. Today, the United States is the only state able to provide either of these beyond its own territory, especially on the great “commons” of the sea. Thus, according to this view, the United States today must lead the other maritime commercial states in an effort to end piracy, just as Great Britain did during the 19th century.

But there are major practical problems with doing so. The first is the vast sea area, about four times the size of Texas, in which the Somali pirates operate. Patrolling an area with about 1300 nautical miles of coastline requires a huge commitment of naval resources. In fact, at any one time, the U.S. 5th Fleet has 5-10 ships in the area. That commitment is complemented by both an EU naval force and a NATO fleet. Several other countries, including China, Russia, India, Saudi Arabia, and Malaysia, have provided naval assets for anti-piracy operations in the area or will soon do so. But the area is simply too large for a continuous naval presence sufficient to deter or defeat the pirates.

Then there is the political economy of Somali piracy, which has created a network that provides intelligence, sanctuary, funding, and the “mother ships” that provide the pirates with the “reach” they need for their depredations. Additionally, the pirates have demonstrated a remarkable ability to adapt to changing circumstances, avoiding the Somali coast in order to thwart anti-piracy patrols, docking at ports in other countries to refuel and lay on supplies.

But the elimination of piracy is more a question of will than of resources per se. Piracy (along with the slave trade) was crushed in the 19th century when the states of Europe, rather than tolerating the practice as they had done in the 17th and 18th centuries, decided to take action. The effort was led by Great Britain, with the Royal Navy as the primary instrument. What made the actions successful was the determination of Great Britain and others to attack the source of piracy. The Royal Navy in particular not only captured and sank pirate ships, but also attacked pirate sanctuaries, destroying their bases.

In the 19th century, the United States also played a role in ending the piratical forays of the Barbary States of North Africa. This is one of the reasons why it has been nearly two centuries since pirates last attempted to seize a vessel flying the American flag.

After losing the protection of Great Britain as a result of America’s Declaration of Independence, American ships were preyed upon by the Barbary States—Algiers, Tunis, Morocco, and Tripoli (today’s Libya). Like the Europeans during the same period (and most maritime states today), the Americans deemed the cost of military action too high and opted to pay “tribute” to the Barbary States. But the demands for these bribes kept growing while the seizure of U.S. ships only increased.

Congress authorized the construction of several frigates and President Thomas Jefferson dispatched them in 1801 for “policing actions” in the Mediterranean after the pasha of Tripoli declared war on the United States. During the next several years, the fledgling American Navy bombarded the harbors of Algiers, Morocco, and Tunis or threatened them with bombardment. As a result of these actions, these states agreed to cease cooperating with Tripoli. But the pasha remained defiant.

In 1804, a naval force under Captain Stephen Decatur boldly sailed into Tripoli harbor, where he set fire to the captured USS Philadelphia, later rescuing its crew, bombarding the fortified town, and boarding the pasha’s own fleet where it lay at anchor. In April 1805, Captain William Eaton led an expedition consisting of U.S. Marines, mercenaries, and Arab rebels across many miles of desert to take Tripoli’s second city, Derna, by surprise, largely ending the depredations of the Barbary pirates against U.S. ships in the Mediterranean.

To adopt such an approach to piracy today, however, would require a return to a distinction in the traditional understanding of international law, one that did not extend legal protections to individuals who do not deserve them. This distinction was first made by the Romans and subsequently incorporated into international law by way of medieval and early modern European jurisprudence, e.g. writings on the law of nations by such authors as Hugo Grotius and Emer de Vattel.

The Romans distinguished between bellum, war against legitimus hostis, a legitimate enemy, and guerra, war against latrunculi—pirates, robbers, brigands, and outlaws—“the common enemies of mankind.” The former, bellum, became the standard for interstate conflict, and it is here that the Geneva Conventions and other legal protections were meant to apply. They do not apply to the latter, Guerra—indeed, punishment for latrunculi traditionally has been summary execution, although the extreme punishment was not always exacted. The point is that until recently, no international code has extended legal protection to pirates.

As Grotius wrote in Mare Librum (The Free Sea), “all peoples or their princes in common can punish pirates and others, who commit derelicts on the sea against the law of nations.” And more forcefully, Vattel wrote in his 1738 treatise, The Law of Nations, that “legitimate and formal warfare must be carefully distinguished from those illegitimate or informal wars, or rather predatory expeditions, undertaken, either without lawful authority, or without apparent cause, as likewise without the usual formalities, and solely with a view to plunder.”

Once this distinction is revived, it opens the way for the only real way to stamp out piracy, as was done in the 19th century: the use of force to wipe out the pirate lairs. Under the old understanding of international law, a sovereign state has the right to strike the territory of another if that state is not able to curtail the activities of latrunculi.

As John Locke understood, pirates are in a “state of nature” relative to political society. And political society has the right to defend itself against such individuals:

“That, he who has suffered the damage has a right to demand in his own name, and he alone can remit: the damnified person has this power of appropriating to himself the goods or service of the offender, by right of self-preservation, as every man has a power to punish the crime, to prevent its being committed again, by the right he has of preserving all mankind, and doing all reasonable things he can in order to that end: and thus it is, that every man, in the state of nature, has a power to kill a murderer, both to deter others from doing the like injury, which no reparation can compensate, by the example of the punishment that attends it from everybody, and also to secure men from the attempts of a criminal, who having renounced reason, the common rule and measure God hath given to mankind, hath, by the unjust violence and slaughter he hath committed upon one, declared war against all mankind, and therefore may be destroyed as a lyon or a tyger, one of those wild savage beasts, with whom men can have no society nor security: and upon this is grounded that great law of nature, Who so sheddeth man’s blood, by man shall his blood be shed.”

The United States acted in accord with this understanding in the early 19th century. In response to raids from Spanish Florida by Creeks, Seminoles, and escaped slaves, General Andrew Jackson, acting on the basis of questionable authority, invaded Florida, not only attacking and burning Seminole villages but also capturing a Spanish fort at St. Marks. He also executed two British citizens whom he accused of aiding the marauders.

Most of President James Monroe’s cabinet, especially Secretary of War John Calhoun, wanted Jackson’s head, but Secretary of State John Quincy Adams came to Jackson’s defense. He contended that the United States should not apologize for Jackson’s preemptive expedition but should insist that Spain either garrison Florida with enough forces to prevent marauders from entering the United States or “cede to the United States a province, which is in fact a derelict, open to the occupancy of every enemy, civilized or savage, of the United States, and serving no other earthly purpose than as a post of annoyance to them.” As Adams had written earlier, it was his opinion “that the marauding parties ought to be broken up immediately.” As John Gaddis has observed, Adams believed that the United States “could no more entrust [its] security to the cooperation of enfeebled neighboring states than to the restraint of agents controlled, as a result, by no state.”

Unfortunately, we have permitted legalism and moralism to twist our understanding of the “rule of law” into something that Grotius, Vattel, Locke, or the Founders would no longer recognize. For instance, European navies have been advised to avoid capturing Somali pirates since under the European Human Rights Act, any pirate taken into custody would be entitled to claim refugee status in a European state, with attendant legal rights and protections.

Americans must understand that if we really wish to root out piracy today, we must be willing to take strong steps. But these steps will require us to change the current mindset, which does not distinguish between war against legitimate enemies and war against “the common enemies of mankind,” which include not only pirates but also terrorists.