Louis Rene Beres

Professor of International Law

Purdue University

LAEB Building

West Lafayette IN 47907

TEL 317 494-4189

FAX 317 494-0833


Assassination is prohibited at Executive Order 12333 of the United States (December 4 1981) which stipulates, at Part 2, paragraph 2.11: "No person employed by or acting on behalf of the United States Government shall engage in, or conspire to engage in, assassination." Prohibition of assassination is also the "supreme law of the land" because of its prior criminalization under international law. As we shall now see, international law is included in the law of the United States.

When two states are at war, assassination is normally treated by international law as a war crime. According to Article 23(b) of the regulations annexed to Hague Convention IV of October 18, 1907: "It is especially kill or wound treacherously individuals belonging to the hostile nation or army." U.S. Army Field Manual 27-10, THE LAW OF LAND WARFARE (1956), incorporates this prohibition and authoritatively links Hague Article 23(b) to assassination.

Hague Convention IV is a treaty of the United States and is, therefore, the "supreme law of the land" under the Article 6 "Supremacy Clause." Hence, even if the U.S. Congress were ever to decide to enact a statute that expressly repealed the rule found at Hague Regulation 23(b), that would not permit U.S. officials to legalize assassinations. This is because, inter alia, the Nuremberg Tribunal ruled conclusively that the obligations codified at the Hague Regulations had entered into customary international law. Such law, of course, is recognized as binding at Article 38 of the Statute of the International Court of Justice.

When two states are at peace, assassination is normally treated by international law as one or more of the following crimes: aggression; terrorism; or intervention. For example, the U.N. General Assembly Definition of Aggression (1974) criminalizes "...the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State...." The Convention on the Prevention and Punishment of Crimes Against Internationally Protected Persons, a treaty against terrorism, criminalizes "The intentional commission of a murder, kidnapping or other attack...." upon public officials. As for the rule of nonintervention, which may be violated by assassination, it can be found especially at customary international law, in the U.N. Charter, the Charter of the Organization of American States, the Convention on Rights and Duties of States and in the Convention Concerning the Duties and Rights of States in the Event of Civil Strife.

The United States is bound by all of these prohibitions. It is, apparently, plainly impossible for the Congress or the President to legalize assassination. Should the prohibitions be disregarded, our responsible high officials would seemingly be subject in principle to prosecution under international law as "common enemies of mankind" in any state that claimed universal jurisdiction. U.S. law accepts and reinforces these particular global obligations. According to paragraph 498 of Field Manual 27-10, any person, whether a member of the armed forces or a civilian, who commits an act that constitutes a crime under international law, is responsible for the crime and is liable to punishment.

There are many sources that point to the convergence of national and international law. According to Article 6 of the Constitution, "All treaties made...under the authority of the United States shall be the supreme law of the land...." Although Article 6 refers exclusively to treaties, the process of incorporation has also been extended by the Supreme Court to other sources of international law. As this means that all of the international rules against assassination are now the law of the United States, any attempt to modify prohibitions against assassination would also be in apparent violation of U.S. municipal law.

Those who would ask for a broader right of assassination must also recall that the President of the United States has taken an oath required by Article 2, Section 1, Clause 7 of the Constitution "to preserve, protect and defend the Constitution of the United States." In view of Article 6 and the pertinent Supreme Court judgments, this signals that the president is sworn to uphold the international law prohibitions concerning assassination. Similarly, Article 2, Section 3 requires the President to "take care that the laws be faithfully executed," a charge that extends to respect for the lives of public officials in other states.

It would appear certain, on the basis of what we have just considered, that any attempts to undermine the operative executive order dealing with assassination is bound to be illegal. An executive order is inferior to prevailing federal statutes. But even if an authentic public law were passed allowing assassination in certain instances (an absolutely inconceivable prospect, in light of essential secrecy requirements), it would be inferior, under the U.S. Constitution, to already-incorporated international law.

These arguments notwithstanding, there are certain instances where assassination may not represent a violation of international law. Indeed, there are circumstances where assassination may be authentically law-enforcing? How can this be, in view of the authoritative and seemingly ironclad prohibitions just discussed?

The answer lies in the principle of jus cogens or "peremptory" norms of international law. According to Article 53 of the Vienna Convention on the Law of Treaties, "A peremptory norm of general international a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character." Even a treaty must always be subordinate to peremptory expectations. "A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law."

Among the most ancient and "sacred" peremptory norms is Nullum crimen sine poena, "No crime without a punishment." Where crimes are especially egregious, as in the case of Nuremberg-category crimes (crimes of war; crimes against peace; and crimes against humanity ), this expectation is altogether overriding. It follows that where known perpetrators of such egregious crimes, including certain crimes of terrorism, cannot be punished by "normal" judicial remedy, i.e., extradition and prosecution, the choice will be to leave these perpetrators unpunished or to punish them extra-judicially. Here, assassination, subject of course to the constraints of discrimination, proportionality and military necessity, may be the least costly form of extra-judicial punishment. Moreover, where crimes are still ongoing, the permissibility of assassination could be even greater, as an additional peremptory norm would be supported by such an extraordinary remedy - that is, the obligation in our post-Nuremberg world legal order to protect human beings from clear and terrible infringements of their irreducible and immutable rights.

Let us consider a concrete example. Since the end of the Gulf War, Saddam Hussein has continued to kill and displace thousands of Kurds and Shiite Arabs within Iraq. Leaving tactical difficulties aside, assassination of Saddam could have spared at least these many innocent lives. Supporting the peremptory expectations of both punishment for crimes and regard for essential human rights, such extra-judicial execution would have been distinctly law-enforcing. Looking back, it has surely been a greater violation of international law to leave Saddam's rule intact than it would have been to assassinate him. Even though such action would have compromised another peremptory expectation known as "due process of law," there are times when the very lives of endangered persons must be regarded as overriding in importance.

Understood as tyrannicide, assassination has long been considered to be lawful. Support for such a form of assassination can be found in Aristotle's POLITICS, Plutarch's LIVES, and Cicero's DE OFFICIIS. According to Cicero:

There can be no such thing as fellowship with tyrants, nothing but bitter feud is possible: and it is not repugnant to nature to despoil, if you can, those whom it is a virtue to kill; nay, this pestilent and godless brood should be utterly banished from human society. For, as we amputate a limb in which the blood and the vital spirit have ceased to circulate, because it injures the rest of the body, so monsters, who under human guise, conceal the cruelty and ferocity of a wild beast, should be severed from the common body of humanity.

The 18th century Swiss scholar, Emmerich de Vattel, in THE LAW OF NATIONS, recalls that "the essential object of civil society" is to "work in concert for the common good of all." Hence, he inquires:

Could the society make use of its authority to deliver irrevocably itself and all its members to the discretion of a cruel tyrant? Surely not, since it would lose all rights of its own if it undertook to oppress any part of the citizens. When, therefore, it confers the supreme and absolute power of government without express reserve, there is necessarily an implied reserve that the sovereign will use that power for the welfare of the people, and not for their destruction. If he makes himself the scourge of the State, he disgraces himself; he becomes no better than a public enemy, against whom the Nation can and should defend itself. And, if he has carried his tyranny to the extreme, why should the life itself, of so cruel and faithless an enemy, be spared?

Where it is committed internationally, tyrannicide might, in certain instances, also be defended as permissible or even law-enforcing. Here the defense of assassination would derive from the overriding obligation to support the authoritative human rights regime in a decentralized system of international law. Although the reasonableness of such a defense might be based entirely on expectations of Nullum crimen sine poena, it could be augmented where particularly egregious crimes and/or "grave breaches" are still underway. In these cases, transnational assassination would represent an expression of humanitarian intervention.

Of course, for assassination to be a law-enforcing expression of humanitarian intervention, a number of pertinent criteria would need to be satisfied. First, the assassination itself would have to be limited to the greatest extent possible to the authoritative persons within the offending state. Second, the assassination would have to conform to all of the settled rules of warfare as they concern discrimination, proprtionality and military necessity. Third, the assassination would need to follow intelligence assessments that point "beyond a reasonable doubt" to ongoing and egregious human rights violations. And fourth, the assassination would need to be founded upon carefully-calculated judgments that it would in fact remedy the precipitating human rights violations, and that it would do substantially less harm to civilian populations than would the alternative forms of humanitarian intervention.

These determinations could be exceedingly problematic, and might, individually or collectively, be founded upon erroneous information or assumptions. Nevertheless, the only alternative to such problematic determinations in our decentralized system of international law is: (a) a general renunciation of humanitarian intervention as a remedy for major crimes; or (b) a general reliance upon broader uses of force as instruments of humanitarian intervention. Recognizing that (a) would assuredly produce legions of innocent human victims each year; and that (b) would represent a far costlier means of law-enforcement, assassination should not be dismissed out of hand as an expression of humanitarian intervention.

The utilitarian view here is that human actions should be evaluated in light of their consequences and that only this consequentialist approach will enable us to deal with complex moral and legal issues in a rational, clear, objective and precise fashion. The principle of utility, which has its relevant origins in Jeremy Bentham's INTRODUCTION TO THE PRINCIPLES OF MORALS AND LEGISLATION, is "...that principle which approves or disapproves of every action whatsoever, according to the tendency which it appears to have to augment or diminish the happiness of the party whose interest is in promote or to oppose that happiness." A good utility-based argument against those who would claim that assassination is impermissible because it arouses antipathy is Bentham's statement against the principle of sympathy and antipathy which "approves or disapproves of certain actions, not on account of their tending to augment the happiness of the party whose interest is in question, but merely because a man finds himself disposed to approve or disapprove of them: holding up that approbation or disapprobation as a sufficient reason for itself, and disclaiming the necessity of looking out for any extrinsic ground."

In the final analysis, whether or not assassination can be construed properly as lawful or even law-enforcing derives from the persistently Westphalian logic of international law, from the multiple sources of international law identified at Article 38 of the Statute of the International Court of Justice, and from the frequently irreconcilable nature of competing peremptory norms. Were the world legal order more effectively centralized and/or the mechanisms of extradition and prosecution more reliable and well-developed, resorts to assassination as permissible would likely be an oxymoron. But in the absence of a capable supranational authority and of a viable enforcement apparatus in the extant system, assassination may, however regrettably, have its limited and proper place.

The above arguments regarding assassination are strengthened by the underlying and all-important expectations of natural law, expectations that are always peremptory, are always above the particular constraints of human lawmaking, and always of special relevance to Americans. For Blackstone, writing in the Fourth Book of his Commentaries, "Of Public Wrongs," it was essential to transform "the eternal, immutable laws of good and evil" into a practical and operational code. As a starting point for understanding the common law, the Commentaries reveal that all international law, or what Blackstone calls the "law of nations," is "deducible" from natural law and therefore binding upon each and every state. Thus, each state is called upon "to aid and enforce the law of nations, as part of the common law, by inflicting an adequate punishment upon offenses against that universal law...."

When Thomas Jefferson set to work on the Declaration of Independence, he drew freely upon Aristotle, Cicero, Grotius, Vattel, Pufendorf, Burlamaqui and, especially, John Locke. Asserting the right of revolution whenever government becomes destructive of "certain unalianable rights," the Declaration posits a natural order in a world whose laws are external to human will and which are discoverable through human reason. Although, by the eighteenth century, scholars had come to view God as having withdrawn from immediate contact with humankind (thereby transforming God into the prime mover of the universe), "nature" provided an apt substitute. Reflecting the decisive influence of Isaac Newton, whose Principia was first published in 1686, all of creation was now taken as an expression of divine will. Hence, the only way to know God's will was to discover natural law. Locke and Jefferson had deified nature and denatured God.

The theory of natural law, which is found, inter alia, in the Declaration and in the Bill of Rights, is based on clarity, self-evidence and coherence. Its validity cannot be challenged by considerations of power politics. To ignore any assassination imperatives that might lie latent in these documentary foundations of the United States - in particular, as we may witness egregious international crimes - would be illogical and self-contradictory, as it would nullify the immutable and universal law of nature from which these documents derive.

We may see, therefore, that U.S. responsibility to ensure punishment and protect human rights derives not only from the explicit expectations of international law, but also from the natural law foundations of American municipal law. In the strictest sense, the natural law foundations of our municipal law are not a distinct alternative to international legal norms, but rather a distinct source of international law. According to Article 38(c) of the Statute of the International Court of Justice, international law stems in part from "the general principles of law recognized by civilized nations." This means nothing less than that the U.S. Declaration of Independence and Bill of Rights represent an authoritative source of international legal norms. Indeed, contemporary international law displays an even more explicit debt to these documents by identifying an "international Bill of Rights" as the very cornerstone of a binding, worldwide human rights regime. It follows from all this that any U.S. initiative to punish and prevent certain international crimes by assassination could represent essential support for international law directly and for our own founding principles.

Where, exactly, must we now stand on the subject of assassination? In essence, we have seen that assassination is both patently illegal and overwhelmingly lawful or even law-enforcing. Which judgment is correct? What should be the correct position of American policymakers on this delicate subject?

To answer this question we should first recall that this country has, as an incontestable matter of fact, engaged in assassination, both in time of war and in time of peace. Whatever the status of pertinent prohibitions, our leaders have, on occasion, decided for themselves that assassination is purposeful, that it is "cost-effective" for the national interest.

During the Cold War, several U.S. presidents are authoritatively alleged to have approved assassination of certain foreign leaders. These targets of assassination included Cuba's Fidel Castro (unsuccessful) and Chile's Salvador Allende (successful). According to a Select Senate Committee that studied these plots, "United States Government personnel plotted to kill Castro from 1960 to 1965. American underworld figures and Cubans hostile to Castro were used in these plots, and were provided encouragement and material support by the United States." William Colby, former Director of CIA, has corroborated this assessment:

The most significant consequence of the Cuban Missile Crisis was that it exacerbated the Kennedy's fury over Castro and intensified their determination to use the CIA and its covert action capability "to get rid of him," with all the ambiguity the phrase includes. For this purpose, that ace clandestine operator Desmond Fitzgerald was transferred to head the special Cuban Task Force....While Operation Mongoose...was soon disbanded, Fitzgerald, under Robert Kennedy's close scrutiny, launched a series of operations...against Cuba. And this campaign included renewed attempts to assassinate Fidel Castro, which had started in 1960 and were sporadically prosecuted from 1961 to 1963.

The "successful" assassination of Allende grew out of the Chilean coup of September 11, 1973. Moreover, a Select Senate Committee concluded that in addition to the Cuban and Chilean cases, and to particular cases involving Congo, the Domincian Republic and South Vietnam, ranking officials of the United States Government authorized "a generalized assassination capability" within the Central Intelligence Agency. From the standpoint of national and international law, however, these assassination plots were all illegal. Although they were likely conceived with the intent of enhancing this country's national security, they were assuredly a manifestation of concern not for peremptory norms of international law, but for Realpolitik. Such concern is not a permissible rationale for any transnational use of force, including assassination. And although there may be a residual right of assassination as a particular form of anticipatory self-defense (in addition to the rationales offered above), there was never any reason to believe that threats posed by Cuba and Chile were sufficiently immediate and overwhelming to warrant the invocation of this right.

Now, what about this country's resorts to assassination during a war? Enemy officials may meet the requirements for combatant status, not enemies hors de combat, under international law so long as they operate within the military chain of command. Enemy officials, therefore, may qualify as lawful targets under this reasoning. Under these assumptions, international law may permit assassination of enemy leaders provided that the victim qualifies as a combatant under the laws of war. This contrary argument, however, effectively ignores the position codified by the Hague Convention No. IV at Article 23(b).

International law may permit assassination of enemy officials during wartime despite the contrary rule of Hague Convention No. IV because: (a) technically, assassination could be construed to fall outside the scope of behavior designed "to kill or wound treacherously," and (b) under certain circumstances the necessity of assassinating an enemy official overrides applicable treaty prohibitions. The first rationale relies primarily on a "linguistic" solution to the conflict while the second rationale invokes the historic natural law origins of international law.

In the United States, William Colby, former Director of Central Intelligence, argues that this country should refrain from assassinations except during "active war situations." Consistent with this position, Colby headed the very controversial Phoenix Program during the Vietnam War which identified and rooted out the "secret Communist apparatus" within South Vietnam - the so-called Viet Cong Infrastructure (VCI). Working closely with the Special Branch of the Vietnamese Police, Phoenix (or "Phung Hoang" in Vietnamese) operatives assisted and carried out assassinations against the VCI. Because Phoenix had no committed forces of its own, external units with the means for such operations probably carried out the actual killings. According to Colby, this included "the military, the police, the amnesty program, and the local administration," which "mounted the actions against the suspects identified by Phoenix." Nonetheless, official agencies of the United States unquestionably maintained responsibility in these assassinations.

From the standpoint of national and international law, these United States-sanctioned killings represented clear and egregious violations of humanitarian international law. Without even considering antecedent questions concerning lawfulness of the war itself, questions of "Just War" or jus ad bellum, these assassinations contravened the codified and customary rules of armed conflict, rules of international law fully incorporated into U.S. municipal law. No jus cogens or peremptory norms existed to override these codified and customary prohibitions of assassination.

This does not mean that national and international law always necessarily prohibits assassination during wartime. Had the Allies succeeded in assassinating Hitler or Mussolini during World War II, or had the Coalition forces assassinated Saddam Hussein during the Gulf War, these efforts would have constituted legitimate, law-enforcing measures. A utilitarian or balance-of-harms calculation would have supported this conclusion. In contrast to the Phoenix-directed assassinations during the Vietnam War, the killings of Hitler, Mussolini and Saddam would have lessened greatly the amount of total suffering in war and after war, hastened the processes of war-termination and fully coincided with the binding expectations of discrimination, proportionality and military necessity.

Abhorrent as it may seem, assassination does have its proper place as enforcement under international law. To be sure, this place is small and residual, but it must still be acknowledged. Although an optimal world legal order would contain neither victims nor executioners, such an arrangement of global power and authority is assuredly not on the horizon.

From the particular standpoint of the United States, past abuses, double-talk and double-standards concerning assassination should not prevent such an "extraordinary remedy" from achieving more purposeful and lawful expressions. Assassination, like war, will not simply go away. The point, therefore, is not to pretend and to manipulate, but to operate within clear constraints and jurisprudentially correct standards. Ideally, our leaders - in conjunction with others in the United Nations - would soon set to work on a "Draft Code" concerning assassination. An expected outcome of such a codification effort, which would have substantial precedent in international law, could be a stricter regulation of assassination as a transnational activity and corollary reductions in associated peripheral harms (reductions bringing assassination within the ambit of humanitarian international law). The only alternative is "business as usual," pretending that assassination is not a matter of concern under international law. Such pretense will not inhibit the incidence of assassination and it will certainly ensure a continuing incapacity to bring such killing under effective guidelines and control. If we can accept that so intrinsically an uncontrollable activity as war should be regulated by law, we should also be able to accept codified regulation for assassination.

Significantly, such acceptance would be perfectly consistent with certain classical writings on the subject, writings identified, at Article 38 of the Statute of the International Court of Justice, as an authoritative "subsidiary means for the determination of rules of law." For example Cicero, in his speech in defense of Milo, supports assassination, inter alia, as anticipatory self-defense:

But if there be any occasion on which it is proper to slay a man - and there are many such - surely that occasion is not only a just one, but even a necessary one, when violence is offered, and can only be repelled by violence....What is the meaning of our retinues, what of our swords? Surely it would never be permitted to use to have them if we might never use them. This, therefore, is a law, O judges, not written, or read, but which we have taken and sucked in and imbibed from nature herself; a law which we were not taught, but to which we were made - which we were not trained in, but which is ingrained in us - namely, that if our life be in danger from plots, or from open violence, or from the weapons of robbers or enemies, every means of securing our safety is honorable. For laws are silent when arms are raised, and do not expect themselves to be waited for, when he who waits will have to suffer an underserved penalty before he can exact a merited punishment.

Elsewhere in the same speech, Cicero offers enthusiastic support for assassination as tyrannicide:

Grecian nations give the honors of the gods to those men who have slain tyrants. What have I not seen at Athens? What in the other cities of Greece? What divine honors have I not seen paid to such men? What odes, what songs have I not heard in their praise? They are almost consecrated to immortality in the memories and worship of men. And will you not only abstain from conferring any honors on the saviour of so great a people, and the avenger of such enormous wickedness, but will you even allow him to be borne off for punishment? He would confess - I say, if he had done it, he would confess with a high and willing spirit that he had done it for the sake of the general liberty; a thing which would certainly deserve not only to be confessed by him, but even to be

boasted of.

We have come full circle. Although we should surely hesitate to commend assassination as a remedy "to be boasted of," even in the most residual and reasonable circumstances, we should just as surely recognize it reluctantly as a remedy that is sometimes indispensable. From the point of view of the United States, the imperative I have prescribed is that we abandon assassination altogether as a cynical weapon of Realpolitik (more often than not, a weapon that is not only employed illegally, but also counterproductively), but that we maintain under very limited conditions its operational capabilities. As we have just seen, these assassination capabilities must be conceived and used very narrowly with particular respect to the peremptory expectations of humanitarian intervention and/or anticipatory self-defense. Their proper function is to save lives, to confirm our understanding that this is not yet "the best of all possible worlds" and that, sometimes, the reluctance to use such force will only produce more corpses.


LOUIS RENE BERES (Ph.D., Princeton, 1971) is the author of fourteen books and several hundred scholarly articles dealing with international law. He is Professor of Political Science and International Law at Purdue University.