In response to the bewilderment of the public after the leaking of the so-called "torture memo" in 2004, a senior official in the Bush administration recalled that the juridical status of "illegal enemy combatant" was hardly the product of recent political and legal history. "Why is it so hard for people to understand that there is a category of behavior not covered by the legal system? He asked. What were pirates?"

What were pirates indeed, and how did legal authorities deal with the ominous presence of these criminal seafarers? Until a recent past, the pirate could largely be considered a minor figure in the law of nations. An ancient lawyer, statesman, and philosopher such as Cicero alluded to him as "the common enemy of all" in order to mark the outer limits of the domain of duties and obligations due to "the immense fellowship of the human species." "For a pirate is not included in the number of lawful enemies, but is the common enemy of all," Cicero remarked in his De Oficiis. "With him there ought not to be any pledged word or any oath mutually binding."

To the lawful enemy a promise must be kept. Not so for the pirate: nothing is owed to him because he lives without "good faith". In dealing with the common enemy of all, one must act exactly as he does: faithlessly. Since "enemies of all" are neither criminals nor belligerents in any accepted sense, the operations carried out against them cannot be formally identical to those employed against a lawful enemy. A medieval glossator such as Bartolus could exclude the pirate from his discussion of ius belli on the grounds that lawful enemies are always sovereign public persons, while the pirate, by contrast, is no more than "the enemy of the human species."

Some authors introduced a distinction between the pirate and the corsair or the privateer. This distinction allowed the medieval and modern authorities to confer formal legitimacy on banditry at sea, producing a legal thing unknown to the ancient world: a veritable license to plunder. For these authors, to identify the corsair with the pirate is "to confuse the voluntary soldier with the thief, the hero with the bandit. The course is one means among others to wage maritime war. Piracy is a crime against the rights of nations." But while in some sense established, this distinction could not be defined with any satisfactory legal exactitude, and privateers were often treated as no more than pirates, outlawed by the laws of nations.

Enlightened jurists, such as Grotius, Pufendorff, Wolff and Vattel, also invoked the specter of the pillager's unruly criminality, conjuring images of "wild monsters of the human species," "unworthy of the name of men," whom all must remove from their midst. They did so from the perspective of the ius gentius, but also in their effort to codify maritime law. By Roman law, flowing water, both within the territory and beyond the shores, was by nature free from claim of ownership. The ancients accepted that the seas could have no lawful master. In 1609, Grotius famously defended the Freedoms of the Seas, in a Dissertation on the Rights that Belongs to the Batavians to take Part in East Indian Trade. By the eighteenth century, it could be considered an established legal principle that the world's oceans lay beyond the rightful reach of any sovereign power. As a consequence, "depredations committed on the seas by certain lewd and ill-disposed persons", as piracy was defined, were offenses committed against all nations, and any state authority could legitimately take possession of the vessel and prosecute those on board.

But those were all references to marginal antagonists, allusions to bands of exceptional criminals and unlawful enemies who emerged, from time to time, at the edges of the sphere of European public right. Today, as Heller-Roazen argues, the pirate as the ultimate "enemy of humanity" provides the key to the state of perpetual war in which we may well have entered. Four distinctive traits define him: a region beyond territorial jurisdiction, such as the sea, the air, but also "failed" or "rogue" states; agents who display a radical antagonism that makes them "common enemy of all"; the collapse of legal categories such as the distinction between the belligerent and the criminal, or war and crime; and the transformation in the means to fight and prosecute these "enemies of the human species". Pirates are no longer limited to the seas. Today the classic relation between the pirate and his zone of operation has been inverted. Wherever an "enemy of all" can be found--upon the seas, in the air, or on the land--, there a zone of exception will emerge. There the regular statutes of the law, be they civil or martial, may not apply.

Daniel Heller-Roazen claims that his perspective in The Enemy of All is philosophical and genealogical. As he notes toward the end, "an enumeration, analysis, and typology of the various figures of universal enmity in the present would be of immense utility. But it would lie beyond the aims and terms of this book." These precautionary remarks notwithstanding, Heller-Roazen's essay is of direct political relevance, and his implications are bold and far-reaching. His finale, where he subverts and turns on its head Kant's Toward Perpetual Peace, is absolutely stunning. To borrow the words of the poet, the reader is left in grim despair and awestruck wonder, as despotic anguish plants her black flag on his bowed skull.