Most international lawyers argue that the law of nations is binding only on sovereign states and not on individuals. In other words, the individual offender can be punished only under the law of his own or the injured nation. Furthermore, international lawyers are inclined to argue that when it comes to individuals who violate the laws and customs of warfare, international law—as, say, in the Hague conventions—provides neither courts nor punishments.

Yet, a good case can be made for the view that the common or customary law of nations does in fact permit the trial of individuals and does provide punishment—the death penalty. In the case of piracy this has long been so.

Violations of the laws and customs of legitimate warfare are the very kind, some authorities believe, for which individuals ought to be liable under the law of nations. Not only do soldiers of the Axis powers enjoy the protection of the laws of warfare when they fall into the hands of the United Nations, but these nations bring to trial and punish their own soldiers who violate the laws and customs of legitimate warfare or the principles of civilized criminal law. Why, then, should not enemy soldiers be tried and punished for similar offenses?

The German Supreme Court, during the Leipzig trials, had to acknowledge the fact that the law of nations was binding upon individuals. In the trial involving the Llandovery Castle, the court said: “The fact that his deed is a violation of international law must be well-known to the doer. ... The rule ... here involved is simple and is universally known. ... The court must in this instance affirm [Commander] Patzig’s guilt of killing contrary to international law.”

Since World War I there have been adequate precedents and authority for a belligerent to punish, under its own laws, enemy violators of the laws and customs of war. Both German and American jurists agree that when a state wishes, as a matter of justice, to punish such an offender, the fact that it has not previously enacted a penal code to suit the crime is irrelevant. Thus, an American authority on international law, discussing the case of the saboteurs who were executed in 1942, declared that the decision which our Supreme Court affirmed “is impressive judicial testimony to the effect not only that the law of war ... is a part of the local law, but also that its applicability by the courts ... need not await precise legislative appraisal or definition.”

It would indeed be a mockery of justice for an Axis officer to claim that because no specific code of international criminal law exists, he did not know that such actions as the slaughter or enslavement of innocent civilians, or the torture of prisoners are forbidden.

Should we be bound by the theory that only the state and not also the soldier is liable for his violations of the laws of war? In answering this question it should be remembered that the typical remedies against a state (for example, protest through neutrals, the taking of measures of reprisal, and the imposition of a “fine” by way of postwar indemnity) have been shown by experience in both world wars to be unsatisfactory for making a lawless state respect the laws and customs of warfare. Action against individual offenders is far more effective.

From EM 11: What Shall Be Done with the War Criminals? (1944)