Thus, states attach immense significance even to unproductive or empty land. A state that will no longer assert power to defend its borders is unlikely to continue as a state. If it were wholly indifferent to the distinction between itself and other states, we would suspect some sort of political pathology—for example, the border as a remnant of a dying or dead colonial regime.

That pairing, however, is no more basic than any of the others, including criminal and enemy. The distinction of criminal and enemy is readily available to the popular imagination, deeply rooted in the theory of the modern state, and operates as an organizing principle of institutions and actions. Intuitively, we know that law enforcement and war are not the same.

Organizationally, we distinguish the police from the military. Legally, we distinguish the criminal from the enemy. The organizing thought behind the distinction is that criminals are to be punished for their violation of law, while enemies are to be killed as threats to the sovereign.

The enemy can be killed even when he is literally doing nothing at all. If he is killed, that act is hardly ‘capital punishment’. When he does act, destroying persons and property, he ordinarily breaks no law. Even when he is taken prisoner, he is detained, not punished.

The criminal, on the other hand, is to be punished for what he has actually done, and, for the most part, he is not to be killed. Rehabilitation is an appropriate goal for the criminal, but not the enemy. The criminal is protected by a web of legal procedures that do not extend to the enemy, who may be killed or captured.

These procedures, by extending rights, recognize the personhood of the criminal. The criminal can demand of the state that it justify its actions against him. That, after all, is the meaning of the most basic right to habeas corpus. The enemy, on the other hand, is fundamentally not a person at law. His status determines all that we need to know of him. He is figuratively, if not literally, outside the jurisdiction.

Criminal and enemy both destroy property and life. The meaning of the destructive act, however, depends on how we perceive it. The achievement of the modern nation state was to separate law from sovereignty such that there could emerge a stable distinction of criminals from enemies. The enemy threatens the sovereign; the criminal violates the law. Before the modern era, the distinction tended to collapse in the direction of enemies. Violation of the king’s law had the taint of treason and, more deeply still, of heresy.

The spectacle of the scaffold—the visible deployment of the king’s violence—was as much defeat of the enemy as punishment of the criminal. Pain produced confession, which was a form of surrender. We still hear religious resonances in the term ‘surrender.’ In our increasingly post-modern era, the pressure toward collapse is in the other direction: enemies become criminals. Today, many believe that wars are to end with trials, and warfare should be permitted only as an extension of law enforcement.

The figure of the enemy is constructed from a particular perspective on territory: the enemy penetrates the border. This transgression makes someone an enemy, even if he does relatively little damage and regardless of whether he damages public or private property. Territory, unlike property, is not subject to a comparative valuation.

Borders represent the integrity of the state. Borders in the pre-modern regime tended to be frontiers, where authority was unclear and contested. If the geography that mattered was that of the King’s body, then enemies could appear from anywhere and occupy any place. Their threat was literally to him. In the modern state, there is no singular act of killing that signifies the death of the sovereign.

To eliminate the modern state means to erase its borders. Thus, wars begin with a border penetration; they end when the enemy is driven back across the border. The border has become a geographical representation of national existence. It signifies more than a traditional homeland for an ethnically or religiously defined group.

The logic I have traced has predictable political consequences. A cross-border threat, regardless of how limited, motivates an extreme response. The United States has been in a frenzy of border protection since the penetration of 9/11. Conversely, the enemy must be linked to a threat of border penetration.

Thus, President Bush had to claim that Iraq had weapons of mass destruction capable of reaching the United States. Short of that, how could Iraqis be the enemy? That Iraqis are behaving badly toward each other is not a ground for Americans to sacrifice themselves. They might be criminals, but they would not be enemies.

Of course, the enemy is not always met at the border. Nevertheless, every identification of the enemy must be built on the idea of penetration. We construct a chain of causality that ends at the border. Thus, we hear repeatedly that this threat of penetration justifies our presence in Afghanistan: better there than here. Timothy McVeigh is not the enemy, but a criminal. He crossed no border.