Accountability in the (Post) Ukraine Age of International Law

By: Chile Eboe-Osuji


In a development that some have described as unusually bold—but which some (myself include) saw only as a matter of time—the judges of the International Criminal Court have issued an arrest warrant against Russia’s President Vladimir Putin and one of his ministers for the war crime of deportation or unlawful transfer of people (notably children) from Ukraine to Russia.

In a sense, that particular development has overtaken the debate about its own boldness or inevitability. It is reasonable, of course, for the average person to ask whether Mr Putin would ever be brought to trial at the ICC given the obvious stature of power that he enjoys in the international community. That, of course, remains to be seen.

The eventuality of his prosecution can, however, reasonably actualise a winning wager. This is because no head of state or head of government has ever escaped eventual prosecution—once indicted—in the modern era of international law. That was the fate of Colonel Théoneste Bagosora (who was the effective head of state of Rwanda during the Rwandan Genocide following the death of President Juvenal Habyarimana in a plane crash), Mr Jean Kambanda (the Prime Minister of Rwanda during the genocide), Mr Slobodan Milosević (the President of Serbia), and Mr Charles Taylor (the President of Libera). They were all prosecuted before an international criminal tribunal (Milosević died while on trial). Towards the end of World War II, the Allies had Adolf Hitler (the German Fuhrer) in their sight for criminal prosecution. He escaped that fate by the simple strategy of committing suicide. But his successor as Germany’s head of state, Grand Admiral Carl Dönitz, was prosecuted before the International Military Tribunal at Nuremberg, in the same way that Colonel Bagosora was later tried before the International Criminal Tribunal for Rwanda.

One must go back 104 years to find a case where a head of state was indicted but not ultimately prosecuted. This was the case of Kaiser Wilhelm II, Emperor of Germany and King of Prussia during World War I. He was certainly one of the—if not the—world’s strongest man of his own era. At the end of the Paris Peace Conference of 1919, he was “publicly arraigned” for trial, in the terms of Article 227 of the Versailles Treaty. Alas, he was never tried because he had received asylum in the Netherlands on the eve of WWI’s armistice. The Dutch refused to surrender him to the Entente States for his trial pursuant to Article 227 of the Versailles Treaty. He lived out the rest of his life in asylum in the Netherlands.

Some observers have rued the Dutch refusal to surrender the Kaiser for trial. In my view, however, international law was on the side of the Dutch government on that question. This is because the Netherlands was a neutral country during WWI. As such, the spirit, if not the terms of the 1907 Hague Convention No 5 (respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land) afforded the Dutch an eminently reasonable basis to decline to surrender the Kaiser. This is no occasion to elaborate on the point.

Be that as it may, the “public arraignment” of the Kaiser in Article 227 of the Versailles Treaty, was the first spectre of the new genie of accountability for international crimes that WWI unleashed for even the most powerful heads of state who inflict wars of aggression upon humanity. Until WWI, international law permitted states to do just that if they were strong enough to do so. Aggressors only needed to worry about the resolve of other states—usually led by the United Kingdom—to muster military opposition as an exercise in the balance of power doctrine. There was no legal consequence that aggressors needed to worry about.

WWI changed that calculation. That change was announced in earnest by the political leadership of the United Kingdom and France. To that end, for instance, Sir F E Smith KC, the Attorney-General of England (the future Lord Chancellor Birkenhead), communicated the resolve of his government on 6 November 1918:

“To us it seems that the most effective deterrent of all is that for all ages men who are tempted to follow the wicked and the bloody path which the Governors of the Central Empires have trodden during the last four years, shall have present before their eyes, not a picture merely of the brilliant and meretricious glamour of military success, but also the recollection that in this great conflict punishment attended upon crime.”

Similarly, his political boss, Prime Minister David Lloyd George, insisted that “rulers who plunge the world into all this misery ought to be warned for all time that they must pay the penalty sooner or later.” Therefore, he insisted, the Kaiser “ought to stand his trial.” Lloyd George was not perturbed by the fact that up until then, there was no precedent for the prosecution of a head of state as a matter of international criminal law. “With regard to the question of international law,” he said, “well, we are making international law, and all we can claim is that international law should be based on justice.” That declaration epitomised the reform of international law that the British and French governments were leading, when they insisted that leaders who would in the future unleash wars of aggression must be held accountable in international criminal law.

In the arrest warrant that the ICC has issued against Mr Putin, a preeminent global strong man of the modern era, the genie of accountability is clearly coming almost full circle. To truly come full circle, it is not enough to prosecute him for war crimes. He ought also to be prosecuted for the crime of aggression. It will truly send that message that Lord Birkenhead and Mr Lloyd George were keen to communicate at the end of WWI in relation to the accountability of the most powerful leaders who embark on wars of aggression.


There may be those who may wonder whether Mr Putin enjoys immunity in international law before the ICC or any other international tribunal. That question is comprehensively answered in an upcoming article of mine that will soon be published by the Journal of International Criminal Justice, titled “International Law Rejects Immunity for International Crimes: Full Stop.” An early version of the piece is attached here.

Loss of Belligerent Rights

In a related development, I have another article coming up in the next issue of the German Yearbook of International Law, titled “Rethinking Military Necessity in Wars of Aggression.” I argue in that piece, that the Russian forces are not entitled to the claim of military necessity when they attack civilian residential blocks and flatten them on consideration that they were being shot at from those places in Ukraine. This is because Russian forces are embarked upon an illegal, nay, criminal war in Ukraine. Legal rights do not arise from criminal conduct, in a way that benefit those who are engaged in that criminal conduct.

Indeed, the logic of that reasoning has these two further implications: (i) Ukrainian officials, soldiers or citizens are not legitimate targets for Russians in this war of aggression. In other words, Russians are not entitled to target the President of Ukraine or any other Ukrainian citizen including Ukrainian soldiers. To do so will anchor a charge of murder (for any resulting death), attempted murder or assault (if no death occurs); and, (ii) Russian soldiers captured in Ukraine are not entitled to prisoner of war (POW) status. This does not mean that Ukrainians are entitled to treat them inhumanely. It only means that Russian soldiers can be prosecuted for murder, attempted murder, assault, and unlawful destruction of property. It is true that foot soldiers or field commanders may not be prosecuted under the Rome Statute for the crime of aggression. But that is a different question. That question does not prevent the prosecution of those who launch and fight wars of aggression for the crimes of murder, attempted murder, assault and wanton destruction of property—for every death, injury or destruction of property resulting from their participation in the war of aggression.


It is by pursuing the prosecutorial strategies outlined above can the world truly begin to realise the benefits of what it means to say that wars or aggression are illegal in international law.

Chile Eboe-Osuji

Chile Eboe-Osuji was the President of the International Criminal Court from 2018 to 2021. He is the Distinguished International Jurist and Special Advisor to the President at Toronto Metropolitan University; Paul Martin Senior Professor at University of Windsor; Visiting Professor, University of California Los Angeles School of Law, formerly Distinguished Visitor, University of Toronto Law Faculty; formerly Herman Phleger Visiting Professor of Law at Stanford Law School; and, formerly Senior Fellow, Carr Center of Kennedy School, Harvard University.

Peace as a Fundamental Human Right is Long Overdue


By Chile Eboe-Osuji

“Peace is the most important global public good. … War brings death, human suffering and unimaginable destruction.” —Antonio Guterres

In the observation in the above epigram, the UN Secretary-General sets up the zero-sum value of war relative to peace. It should not be a profound observation in the 21st century. But, there it is: still sounding so profound. And that says so much about the human condition.

In my view, the invasion of Ukraine occurred partly because the international community has not managed—or resolved—to make wars of aggression sufficiently risky (at the personal level) for the world’s war lords.

Russia’s invasion of Ukraine should change that calculation. This can be done by enhancing the legal hazards of war: not only at the more familiar level of criminal prosecution, but also at the level of civil liability that remains largely beyond our consciousness. Both strategies are easy enough to design—but their realisation depends only on the political will of the international community.

I shall presently discuss how to enhance the legal hazards of aggressive war to their authors and accomplices, from the angles of both criminal and civil liability.


Perhaps we may begin the discussion by asking whether this enhancement of the legal hazards of war should be done now. And – – why now?

Why now? It is because we have an overwhelming outrage against a war of invasion, fueling feelings that compel us to do something against wars of aggression. But, we don’t know what to do. Some governments have frozen assets, wondering what to do with them.

Armed conflict has been the greatest driver of the growth of international law.

There’s always the temptation for some to see something of a salutary relationship between war and civilisation—in this case international law. According to that view, war becomes a chief enabler of international law.

But I prefer to see the matter from the perspective of the struggle between a boa constrictor and its prey. Once the boa constrictor wraps itself around its prey, the constrictor tightens grip with every movement the prey makes. That’s what international law does to war.

Some may see that as perhaps too optimistic a view of international law. But consider this:

  • 1648:—Peace of Westphalia often seen as the recognisable yeast of contemporary international law. It resulted from the 30-years and the 80-years wars in Europe that spanned the period 1568 and 1648.
  • 1856:—Paris Declaration often seen as the first international instrument that sought to codify both the principle of neutrality and the proscription of privateering or mercenary activities during war. It resulted from the Crimean War of 1853 to 1856.
  • 1863:—The Lieber Code that was the first attempt to codify the essential elements of the law and customs of war at an early stage. It resulted from the American Civil War.
  • 1864:—The 1st Geneva Convention resulted in the creation of the Red Cross Society and the recognition of the need to provide care and succour to sick and wounded soldiers. It followed the brutality of the 2nd Italian War of Independence that Henry Dunant (a Swiss businessman) witnessed in the Battle of Solferino in 1859.
  • 1868:—St Petersburg Declaration was the first international instrument that sought to make war more humane. It indicated the principle that the weakening of the enemy—rather than total annihilation and wanton cruelty—is the only legitimate aim of war; and it laid down the principle against use of weapons that inflict unnecessary suffering that would make peace more difficult to achieve. The Declaration resulted from the discovery of munitions that would inflict unnecessary suffering.
  • 1899 and 1907:—There were, of course, the extensive international law instruments that resulted from the First and the Second Hague Peace Conferences, respectively in 1899 and 1907. They resulted from the many wars that had blighted life in Europe.
  • 1919:—The Paris Peace Conference of 1919 produced the Versailles Treaty and the Covenant of the League of Nations. The former (in article 227) laid down the unprecedented idea that Heads of State could be prosecuted before international tribunals as a requirement of international law, with no scope at all for the plea of sovereign immunity. The latter instrument introduced for the first time the idea of a standing international organisation with universal remit, to try and foster peace between nations and limit their inclination to make war. The achievements resulted from World War I.
  • 1945:—The conclusion of World War II gave the world the following developments amongst others:
    • The Charter of the International Military Tribunal for Nuremberg and the Charter of the International Military Tribunal for the Far East, which not only unequivocally recognised aggressive war as a crime in international law, but similarly clearly confirmed that Heads of State and Heads of Government may be prosecuted before an international tribunal as a requirement of international law, and that the plea of immunity does not apply.
    • The creation of an updated version of a standing international organisation—the United Nations—to replace the League of Nations.
    • The adoption of the Universal Declaration of Human Rights, in recognition for the first time that human beings are beneficiaries of rights conferred directly upon them by international law.
    • A new international crime—genocide—was nominated for concerted global action in the eponymous Convention on the Punishment and Prevention of the Crime of Genocide.
    • The twin project of formulating an international code of crimes and creating a permanent international criminal court to enforce that code.
  • 1991 to 1994:—Balkan Wars and the Rwandan Civil War resulted in the UN Security Council’s creation of two ad hoc international criminal tribunals—for the former Yugoslavia and for Rwanda. In doing so, the United Nations reiterated the norm that Heads of State are not immune to prosecution before an international tribunal.
  • The events in the former Yugoslavia and in Rwanda also inspired renewed impetus for the creation of a permanent international criminal court that eventually produced the International Criminal Court. A further by-product of the events in the former Yugoslavia and Rwanda was the development of the doctrine of Responsibility to Protect (R2P). It insists that sovereignty entails much more than a vaunting right for the State. It also entails for the State an obligation to protect the domestic population, which if not discharged, would justify intervention coordinated by the United Nations.

The foregoing is a non-exhaustive outline of how armed conflict has enabled the growth of international law.


And here we are in 2022. Another wretched war (waged by Russia against Ukraine), turbo-charging global rage against wars of aggression, which not only visit death and destruction upon innocent victims but also general hardships on the world at large.

It is best to not waste the energy generated by that rage. The better strategy would be to channel all that rage into a productive outcome. It should occasion another adjustment to international law. This is in the manner of enhancing the legal risks—criminal and civil—in ways that must perturb the lords of war.


Currently, the Rome Statute and the ICC comprise the only standing global mechanism against international crimes in general, and the crime of aggression in particular.

There is much more that can be done from the perspective enhancing the risk of criminal prosecution for the crime of aggression. This involves amending the Rome Statute in the following ways:

  • Cover the gap that exists in article 15bis(5), which now excludes persons (or territories) of non-ICC member States from the aggression jurisdiction of the ICC unless the UN Security Council refers the situation to the ICC Prosecutor for investigation and prosecution. That gap can be covered by deleting article 15bis(5), given the fact that the use of the veto power will obstruct the Security Council from referring a situation to the ICC when a P5 member or its client State is implicated in the conduct that needs to be referred to the ICC.
  • Open up article 13(b) of the Rome Statute and allow not only the Security Council, but also the General Assembly (when the veto power has been immorally used to obstruct the Security Council) to refer situations to ICC Prosecutor. Under the amended arrangement, the General Assembly could be left free, at the barest minimum, to recommend such referral to UN Member States—using the “Uniting for Peace” procedure, thus allowing ICC to exercise jurisdiction on the basis of the specific General Assembly resolution to that effect; and
  • Allow the inculpation of not only persons in a position to direct the military or political actions of a state, but also lower-level persons, so they too can be prosecuted for the crime of aggression. This will encourage rank and file soldiers to refuse to obey orders to fight wars of aggression. Thus putting pressure against any Head of State of Government that may conceive of a war of aggression.

These amendments need not be made as a package. Beginning with the first recommendation as the easiest to make, any of the other two or both will immensely enhance the risk of criminal liability for the crime of aggression. It will add layers of deterrence against the crime.

And the great prospect of enhancing that risk through the amendments is that it is entirely up to the member States of the Rome Statute to resolve to make the indicated amendment. It requires no input from the United Nations, let alone a veto power from any member of its Security Council.


Beyond enhancing the hazard of criminal prosecution as indicated above, the strategy of suppressing future crimes of aggression will be significantly shored up by directly exposing aggressive warlords—and their accomplices—to the risk of personal civil liability, universally.

This can be accomplished in the specific manner of adopting an international covenant that specifies peace as an actionable fundamental human right.

As will become clear, this is one strategy that can be employed to enforce international law directly by means of national law and domestic legal processes, a valuable strategy that compensates for the weakness of international law in self-execution.

The scheme of the new treaty can be arranged as follows.

It will begin with the declared premise that all peoples, nations and persons (natural or legal) have a fundamental and inalienable right to peace. That premise will then be the basis of prescribing the acts which would amount to breach of the right to peace. Those acts would obviously include: (i) acts of aggression as defined and explained in the United Nations General resolution 3314 (XXIX) of 14 December 1974; (ii) the launching of sustained internal violent conflict or acts of terrorism by any group of persons in violation of international law; and (iii) complicity or aiding and abetting the conducts indicated in (i) and (ii) above, including by furnishing material assistance to any such conduct.

It won’t be enough to stop at declaring a fundamental right to peace and indicating what would amount to a violation of that right. In light of the doctrine expressed in the maxim ubi jus ibi remedium, it will be necessary to spell out the consequences of such a violation. Here, it will be necessary to provide for a right to reparation, and the modalities of actualising it. The right to reparation would be given to all peoples, nations and persons (natural or legal) who suffer damage as a result of a breach of their right to peace. The right to reparation may be claimed against any person (natural or legal), entity, government or state responsible for the breach or aids and abets it.

The forum for the claim would be any existing or future multilateral, regional or national court or human rights adjudicatory body with jurisdiction to make the award of reparation contemplated in the new covenant. In that regard, each State Party to the covenant should be required to undertake such measures as may be necessary to establish its jurisdiction over claims of reparation contemplated in the covenant, especially when the asset or property of the parties and accomplices to any breach of the right to peace is located within the State. This is how national laws and domestic legal processes will be used to enforce international law in this particular respect.

Additionally, State Parties to this new covenant will be required to cooperate in the execution of any judgment of reparation against any asset or property of any State or person or their accomplices found liable for a breach of the right to peace, wherever such assets or property may be found; without regard to considerations of sovereign immunity.

It is in these circumstances that the earlier question of what to do with frozen assets answers itself. Those assets can remain frozen pending the determination of the claims of victims of wars of aggression. The frozen assets can be used to satisfy those claims.


Past efforts to recognise the right to peace ran into opposition from powerful States concerned that the right to peace may be construed in a manner so broad as to impinge upon the right of States to individual or collective self-defence. Businesses engaged in arms manufacture and trade have also been concerned about the implications of such a right to their commercial interests. 

The imperfections of life must commend a sensible compromise. To begin with, there is no intrinsic incompatibility between the fundamental right to peace and the right of a State to individual or collective self-defence as recognised in international law. The latter includes the right of a State to avail itself of appropriate industry, methods or means of self-defence. That is to say, the right to peace does not stand against the interests of corporations who manufacture and sell weapons that will enable states to engage in self-defence.

But, what the right to peace will—and does need to—stand against would be the selfish interests of businesses inclined to continue to replenish the ways and means of aggressive wars, by selling weapons and other means of perpetuating an act of aggression, when they ought to know that the weapons and means they provide are being used to further acts of aggression.


As we speak, there remains substantial room for the growth of international law in ways that will constrain the space for wars of aggression as a pernicious global phenomenon. Beyond the bleakness of the invasion of Ukraine, the resulting possibility for the development of international law in the suggested way represents a silver lining. The negative global passion unleashed against that war should be harnessed into a positive force for good, as had happened in past wars that occasioned the growth of international law.

The enhancement of the risks against wars of aggression beyond criminal liability, especially by accentuating the strategy of civil claims will make wars of aggression personally costly to the pocketbooks of the authors and accomplices of wars of aggression. The outcome will be to give those culprits further food for thought on whether they truly need to wage a particular war of aggression.

Note: This is the revised summary of a lecture delivered at Stanford University Law School on 10 May 2022.

Chile Eboe-Osuji

Dr. Chile Eboe-Osuji

Chile Eboe-Osuji is the Distinguished International Jurist at the Lincoln Alexander School of Law and Special Advisor to the President. He served as the President of the International Criminal Court in The Hague, from 11 March 2018 to 11 March 2021, and a judge at the Court from 2012 to 2021.

Before the ICC, he worked in various capacities at the UN, including as the Legal Advisor to the United Nations High Commissioner for Human Rights in Geneva, and as a senior prosecution counsel at both the International Criminal Tribunal for Rwanda and the Special Court for Sierra Leone. He practised law as barrister in Canada and Nigeria. He is a recipient of the Goler T Butcher Prize of the American Society of International Law, the Honorary Patronage of the Philosophical Society of Dublin College, and an Honorary Doctor of the University of Middlesex. He received his LLB from the University of Calabar (Nigeria), his LLM from McGill University, and his PhD from the University of Amsterdam (the Netherlands).  

He has written and lectured extensively on international criminal law, international humanitarian law and international human rights law.