In June 1941, the situation for the Allies was bleak. Most of Europe aside from Britain was under Nazi domination. The UK had escaped German invasion but was suffering relentless bombing raids by the Luftwaffe. The US had yet to enter the war.
It was in that grim context that representatives of 14 Allied countries came together in London’s St James’s Palace to issue a statement. When victory seemed distant, the London Declaration proclaimed the Allies’ willingness to fight on. Crucially, it also set the parameters of a future peace. The signatories declared “that the only true basis of enduring peace is the willing cooperation of free peoples” in a world “relieved of the menace of aggression”.
Seeking to eliminate aggression would lead to a new idea in international law: the formal criminalisation of aggression, one of four charges for which Nazi leaders would be prosecuted four years later at the Nuremberg trials. It was a Soviet jurist, Aron Trainin, who theorised what were at first known as “crimes against peace”, arguing that a new category of offence was needed to hold the Nazi leadership accountable for the war. Japanese leaders were also tried for the same crime at the lesser-known Tokyo Trial, which ran from 1946 to 1948.
It was those German and Japanese leaders responsible for triggering the Second World War who were the first to be convicted of the crime of aggression in the 1940s. They were also the last. The world remains tragically burdened with “the menace of aggression”. Wars, from Somalia’s 1977 attack on Ethiopia to the US-led invasion of Iraq in 2003, have not been eliminated in the post-Nuremberg world. None of the leaders responsible for these have ever been prosecuted.
But Vladimir Putin’s invasion of Ukraine, the most blatant war of aggression in postwar European history, has led to calls for Russia to be tried for the crime of aggression. In a speech in The Hague, Netherlands on 4 May, the Ukrainian president Volodymyr Zelensky pushed for Russian leaders to be tried for aggression. “Only one Russian crime led to all of [other war] crimes: this is the crime of aggression,” Zelensky said.
However, prosecuting Russia for the crime of aggression faces formidable political and legal obstacles. What form would the tribunal take? Could the Russian leaders who would be charged be physically apprehended, and if not, should they be tried in absentia? And perhaps most uncomfortably of all, when wars of aggression have been fought around the world since the Second World War, why should the first to be tried in nearly 80 years have happened in Europe?
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Demands to prosecute Russian leaders for the crime of aggression began within days of the 24 February 2022 invasion of Ukraine. But thinking on how to actually do this has only begun to crystallise in the past few months.
Philippe Sands, a British-French international lawyer and the author of East West Street, a memoir on the origins of international criminal law, is one of the leading voices pushing to hold Russian leaders accountable. “The crime of aggression is the waging of a manifestly illegal war,” he told me when I met him recently at the Berlin Jewish Museum, where he was on a panel discussing the history of the Ukrainian city Lviv. “It was put into the Nuremberg Statute [the legal basis for the Nuremberg trials] by the Soviet Union. About 70 per cent of the hearings in Nuremberg were about crimes against peace.”
In theory, the crime of aggression closes a loophole of accountability where soldiers and commanders could be prosecuted for war crimes committed during an invasion, while the leaders who planned and ordered a war of aggression weren’t liable for any other crime. “The crime of aggression is understood as a leadership crime, committed by those representatives of a state who are in a position to give concrete orders to wage a war of aggression,” Anton Korynevych, an official in the Ukrainian Foreign Ministry working on establishing a tribunal to prosecute the war, told me.
In the case of the war in Ukraine, around 20 Russian leaders could be liable for prosecution, Korynevych said, including Putin, Foreign Minister Sergei Lavrov, Defence Minister Sergei Shoigu, and other top ministers and army officials.
These efforts are the most credible attempt to revive the crime of aggression since the Second World War. “The reason that [the charge] has not reared its head after Nuremberg,” Sands told me, “is the big powers have a collective interest in limiting it and diminishing its scope, precisely because they’re concerned about its application to their own military activities.”
Following decades of negotiations, the International Criminal Court (ICC) gained jurisdiction over the crime of aggression in 2018. However, only the leaders of the 45 countries that have ratified an amendment to the 1998 treaty which created the ICC can be tried for it. The biggest military powers, including the US, China and Russia, have not signed up to the clause, meaning the ICC has no legal grounds to try any of their leaders on that charge.
As the ICC lacks jurisdiction over Russia for the crime of aggression, those who want to see Putin and other Russian leaders prosecuted are considering other possibilities. The option favoured by Zelensky and Ukraine’s most fervent supporters in the West is the establishment of a “special international tribunal” for the crime of aggression. A special tribunal is generally set up by the UN to investigate the “core” international crimes.
Special tribunals have been established to prosecute crimes committed in the former Yugoslavia, Rwanda, Cambodia and Lebanon, though never for the crime of aggression. Because Russia is certain to veto efforts at the UN Security Council, a UN-backed tribunal would probably require approval by the General Assembly. Other options include a so-called internationalised tribunal, which would be set up within the Ukrainian legal system with international elements, such as foreign judges.
The precise form the tribunal could take is subject to intense negotiations simply because there has been no precedent for prosecuting the crime of aggression since the 1940s. “Many countries have agreed in principle that the tribunal should exist,” said Anna Rubesame, an international lawyer and founding commissioner of the International Nuremberg Principles Academy, an organisation seeking to build on the legacy of the Nuremberg trials. “What final form it will take has yet to be hammered out.”
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The conflict in Ukraine is hardly the first war of aggression since 1945. Turkey invaded northern Cyprus in 1974, an occupation that continues to this day. Somalia invaded Ethiopia’s eastern, predominantly ethnic Somali Ogaden region in 1977. Russia invaded Georgia in 2008. But one war stands out. “The elephant in the room is Iraq,” Sands told me.
According to the international lawyers I spoke to, the US-led invasion of Iraq meets the threshold of the crime of aggression. It was widely viewed as such at the time, even by officials from the aggressor nations. Elizabeth Wilmshurst, a former legal adviser to the British Foreign Office, resigned in March 2003 on the eve of the invasion, saying that she believed the impending “unlawful use of force on such a scale [amounted] to the crime of aggression”.
The argument for prosecuting Russian leaders and not those responsible for previous wars of aggression, such as the invasion of Iraq, is that the ICC has only had jurisdiction since 2018. That does not include the power to pursue retrospective prosecutions. “This [the war in Ukraine] is probably the first really clear unlawful use of force [since 2018] that meets the very high definition of the crime of aggression,” I was told by Carrie McDougall, an academic at the University of Melbourne and the author of The Crime of Aggression Under the Rome Statute of the International Criminal Court.
Yet this narrow, legalistic argument for indicting Russian leaders over Ukraine is unlikely to sit well with countries in Africa, the Middle East, Latin America and Asia, which see Western countries as having escaped accountability for their own wars of aggression. “Despite the differences between the invasions of Iraq and Ukraine, there are still commonalities, particularly their illegality and flouting of international law,” said Feurat Alani, a French-Iraqi author. “It seems obvious to me that prosecuting Russia cannot be done, morally, without doing the same to George W Bush, Tony Blair and the like.”
A tribunal that tries Russian leaders for the crime of aggression would likely be considered illegitimate by much of the world, particularly if it takes the form of an international court established mostly with the support of Western countries. In our conversation the Ukrainian official Korynevych acknowledged that some states in the Global South have reservations about such a tribunal, but insisted they can be overcome. “It’s not an easy task to bring [the countries of the Global South] fully on-board,” he said. “But I believe that [punishing Russian aggression] is important for the whole world, no matter which country or region.”
Others I spoke to are more sceptical. “I simply don’t believe that a special tribunal supported by less than half of the world’s states – the majority of whom would be in the Global North – would be really seen as legitimate [by the entire world],” Kevin Jon Heller, a professor at the University of Copenhagen and an adviser to the ICC prosecutor Karim Khan, told me. “States in the Global South have a great deal of anger and resentment at the West for its extremely selective and hypocritical approach [to international law],” he added. “Now, all of a sudden, the West wants to create a brand new, fancy international tribunal for the one act of aggression that it cares about?”
In an article for Just Security this January, Luis Moreno Ocampo, an Argentinian lawyer who served as the ICC’s first chief prosecutor between 2003 and 2012, called proposals for a special tribunal an “abuse of law” that would consecrate “selective justice” against only “enemies or outcasts” of the West.
Limited global legitimacy would have practical as well as symbolic repercussions. “No state in the world would be obligated to cooperate” with an international tribunal, according to Heller. Some nations would facilitate the court’s work, but many would not. “Unless the suspects go to one of the states that has chosen to cooperate with the tribunal,” they would be unlikely to face arrest, he added.
In practice, because Russia is not facing the prospect of a total military defeat analogous to the defeat of the Axis powers in the Second World War, it is difficult to see how Putin and other Russian leaders could physically be brought to justice without the cooperation of Russian authorities. If established, a court might be required to try its leaders in absentia, meaning Putin and his subordinates would escape punishment as long as the Russian government is unwilling to hand them over.
Korynevych told me that Ukraine is open to trials in absentia, arguing that they set the groundwork for accountability in the event of political change in Russia. A successor to Putin might find it politically expedient to hand over those responsible for the Ukraine war to face justice. “We need to have the infrastructure and criminal justice institutions which will be ready to take [Russian leaders] if the situation allows. Trials in absentia are something worth thinking about.”
There are no perfect options. Failing to prosecute Russian leaders would signal that, in effect, aggression is a paper crime, too difficult to prosecute even in the most blatant circumstances. “There is a real risk of sending a signal that we’re not serious about the prohibition on the use of force,” McDougall said. “We could see Russia’s [invasion] being replicated by other existing and emerging superpowers who will see quite clearly that there are no criminal repercussions for massive, unprecedented violations of the prohibition of the use of force.”
But if a tribunal to try Russian leaders is successfully established, it is likely to face immediate and lasting challenges to its functioning. Swathes of states across Asia, the Middle East, Africa and South America might perceive it as a prime example of Western hypocrisy. Its legitimacy will be questioned from the outset. Russian leaders may not face accountability for years, if ever. Even so, the Ukraine war offers a unique impetus, unprecedented for almost eight decades, to revive the crime of aggression. Only if the efforts succeed will the London Declaration’s aspiration of a world “relieved of the menace of aggression” have any hope of being realised.
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