Can you start off by telling our readers about the work you’re doing on a special tribunal for the crime of aggression in Ukraine? How would the Special Tribunal be established and what would the legal basis be for its jurisdiction?

I am advising the Ukrainian government and some other States, that I can’t yet disclose, on the creation of a special tribunal for the crime of aggression committed against Ukraine. I am led on this matter by Professor Philippe Sands KC. We have a team of colleagues principally including Professor Dapo Akande, Professor Alex Whiting, and Dr Carrie McDougall has also advised. We work closely with Oksana Zolotaryova, Director General for International Law within the Ministry of Foreign Affairs, and Dr Anton Korynevych, Ambassador-at-Large of Ukraine’s Foreign Ministry, who are leading the effort on the Ukrainian side.

The work is to create a special tribunal. There are four routes to the creation of a special tribunal. To briefly summarise them, the tribunal could be created between Ukraine and a coalition of willing States by way of a treaty. It could be a treaty between Ukraine and the Council of Europe, or Ukraine and the European Union, or Ukraine and the UN Secretary-General on recommendation by the UN General Assembly. But each of those options obviously depends on whether there is political will to do so.

Where would jurisdiction be derived from? Jurisdiction for a special tribunal would be derived from the fact that Ukraine’s domestic statute proscribes the crime of aggression. Coincidentally, so does Russia and Belarus’. And so, essentially because Ukraine proscribes the crime of aggression, this jurisdiction can be delegated to an international tribunal by way of treaty. In addition, general principles of international law can be applied. There’s some contention but it’s largely, I would say, accepted that it’s part of customary international law that key aspects of the crime of aggression are prohibited and a violation of a peremptory norm. This means that, generally, its proscribed in international criminal law.

In combination these two premises are sufficient for the creation of an international or an internationalised tribunal that has jurisdiction. That includes jurisdiction to try senior officials such as Heads of State and Foreign Ministers, who ordinarily would have immunity from prosecution in foreign national courts and immunity from prosecution generally. [This is because] there is said to be, with some contention, an exception to the principles of immunity for serving heads of states or foreign ministers where there is an international tribunal created. So, this is part of the reason why there is a movement not to have a solely Ukrainian tribunal in Ukraine trying the crime of aggression and, also, to address any issues around legitimacy and politicisation that might arise from a domestic only tribunal.

How much support is there for a special tribunal and what objections have been raised regarding establishing one?

I think that in the first month following the start of the invasion, there was a huge amount of goodwill on the part of practitioners, academics, and States, given the scale, nature, and the gravity of the offensive launched by Russia – in concert with Belarus – against Ukraine. Largely, that goodwill has remained even though, as the conflict rages on, there is an inevitable decline in international interest as it falls off the political agenda. That said, momentum hasn’t dissipated altogether.

Regarding objections, I think there is some small but significant opposition for the creation of a tribunal. The principal objections to the creation of the tribunal, as they have emanated from academics, largely legal academics, are that creating a tribunal would: firstly, demonstrate a kind of selective justice given that there’s been other instances of acts of aggression constituting possibly international crimes; secondly, that a tribunal would be costly and it would divert resources from elsewhere; thirdly, that the prosecution of other international crimes such as war crimes, crimes against humanity and, possibly, genocide by other bodies seized of jurisdiction would be more than sufficient to hold senior leaders accountable. I’d say those are the three principal objections, but there are a few others. For example, that political support [for the creation of a special tribunal] is Eurocentric rather than global and, to a lesser degree, a fifth argument about immunity of senior officials in the Russian and Belarusian governments.

My personal view is that each of those five have been largely addressed and addressed very cogently and vociferously. So, I think these objections have largely started to fall away. And I think what remains is essentially political opposition. Issues such as: What precedent would a creation of a special tribunal create? What would it mean possibly for future relationships with the Russian state? How would decisions of a special tribunal be ultimately enforced given that Russia is a very powerful international factor with significant interests?

So, currently, I’d say the only real inhibitor for the creation of a tribunal is political will. And I think, as Philippe Sands and others have said, if major States – France, Germany, Britain, the US – throw their backing behind the creation of a tribunal, then I think that would facilitate and incentivise lots of other States to follow.

Why isn’t prosecuting senior officials for war crimes and crimes against humanity committed in Ukraine sufficient?

The principal reason is international law itself. It’s long been recognised, since Nuremberg, that the supreme international crime is the crime of aggression. And why is it characterised as such? Because if you did not have the initial act of aggression constituting the crime – remember the crime of aggression is a leadership crime that is committed only by political and military leaders – then it’s likely no other crimes would be committed. War crimes wouldn’t have been committed because you would not have war. Similarly, it would also be highly unlikely that crimes against humanity and genocide would be committed as they’re often facilitated in armed conflict situations that create an environment conducive to the commission of these crimes, particularly by armed forces. The crime of aggression is a grave act that is contrary to international law. It’s important that when there is such an egregious violation of international law, committed by individuals, that those individuals are held accountable. It’s a crime not just of concern to one state, it’s a crime of concern to all States given the threat to international peace and security and the violation of a peremptory norm.

You mentioned some critics have said that establishing a special tribunal for the crime of aggression in Ukraine would be ‘selective justice’. Why don’t you believe this is the case?

Firstly, this is not the imposition of a tribunal on an unwilling state. Ukraine has called for the creation of this tribunal. Ukraine has endorsed it. If you characterise it crudely, the victim or survivor state, in this case Ukraine, the call for a special tribunal is emanating from them and we ought to recognise their agency. They wish to have this tribunal. They have a right to it. And arguably, even more than that, an obligation to use the law to its full extent. That is important in and of itself. But it’s also important in the general endeavour and the general right for Ukraine to carry out what would be in law in international law, self-defence, both individual and collective, against an act or acts of aggression against its state, which is also contrary to the prohibition on the use of force – for those interested, Professor Akande has written about the right to self-defence and its scope. And this is another way, and actually a non-binding way, for Ukraine to, let’s say, articulate its self-defence as well as articulate its right to hold accountable those perpetrating core international crimes. I think this really throws away the argument of selectivity because this isn’t a Western imposition of a tribunal against an unwilling state.

Secondly, I think that’s important to distinguish this occurrence of aggression from previous occurrences of aggression in different political climates. We all have in mind, Iraq. But regarding Iraq, if you could characterise that as an act of aggression, and many have, the aggression was different in scale, in nature, in purpose and intent than this occurrence of the act [in Ukraine]. And there wasn’t, as far as I’m aware, a general mobilised call from Iraq itself for the creation of a special tribunal for the crime of aggression there. Had there been, it would have been interesting to see what the international response would have been to such a call from, what was widely recognised as, an authoritarian State run by an authoritarian leader. Certainly, in this way Iraq contrasts to the case of Ukraine where you have a democratically elected government. Ukraine is a State which is part of the Council of Europe. A State which now has an accession agreement with the EU, which is part of the OSCE and a very active member of the international community. So, I think all these reasons really point in the direction of this being a departure from other instances of acts of aggression.

Nevertheless, even absent these political differences, a wrong elsewhere and a possibly poor decision not to address it by the international community does not justify a similar erroneous response today: there is harm that is unquantifiable being done to Ukraine and its people and a form of legal redress is to hold those who are allegedly responsible for the crime of aggression which is the principal source of that harm responsible. Such an avenue ought to be utilised.

Finally, it’s important for another reason: narrative changing and setting a future precedent. Remember that, currently, no court nor international mechanism can be seized of jurisdiction on the crime of aggression. Only a new tribunal or court could try this crime. So, if a new court or tribunal is created with jurisdiction to do so, it will signal to other States that in the future the possibility of accountability or justice is that much greater. That changes the narrative that powerful States can get away with launching acts of aggression which constitute crimes.

Building on your last point. You mentioned before that States including the UK, US and France should get behind the special tribunal. Given that the US hasn’t ratified the Rome Statute and the UK and France haven’t ratified the Kampala Amendment (on the crime of aggression) to the Rome Statute, wouldn’t this create a problem of moral legitimacy if they back a special tribunal for Ukraine?

I think taking a position on Ukraine isn’t mutually exclusive. You can still hold there have been other acts of aggression constituting crimes that have been wrong. It’s unfortunate that tribunals and courts and mechanisms weren’t created to hold those individuals responsible for that. Whether they would have been found guilty or not of the crime, if we have Iraq in mind, is a different matter. It makes absolutely no moral sense to say that there were other acts of aggression historically and, for that reason, the Ukrainian people and its State should suffer, not have accountability and justice. To say that just because there was injustice elsewhere in another time or another occasion that therefore there should be injustice on this occasion too is unjustified. The logical result of this reasoning is that we were wrong in the past, so we will continue to be wrong in the future.

Also, I think we must make distinctions. You know, people have said if the US and UK support this tribunal it’s outrageous. How dare they back this tribunal after what happened in Iraq? But I have two responses to that. Firstly, the UK and US are democratic countries. The new administrations can and often do change policies, change their approach to international law and even their adherence to international law changes. The government of Tony Blair, the Labour government which was in charge of the State during the Iraq war, is very different from the current government in every respect. UK policy has fundamentally changed whether for the better or worse. Since Iraq, the UK has been extremely reticent to engage in military action overseas. Policy often changes with the administrations and for this new administration or future administrations to take a different position in line with international law would be welcome. That’s the first distinction. The second distinction is, well, if the UK and the US and other States in Europe or elsewhere change their position in respect to Ukraine and help create a special tribunal, it makes it much harder in the future for these States and others to launch future acts of aggression. Not just because it would be inconsistent and problematic, but it would signal, I think, morally, legally, and otherwise these acts are proscribed and they’re contrary to international law. There would be an argument both internally in UK domestic policy and internationally to say: look, we took a position here and we ought to adhere to that going forward.

The same goes in respect of ratifications of the Kampala Amendment [on Article 8bis] to the Rome Statute, which brought about the amendment in respect of the crime of aggression. If States sign up to the special tribunal, then of course it makes complete sense that they ought to sign the Kampala Amendment to the Rome Statute. Especially if that’s going to be the definition that would be utilised in a future tribunal it makes it that much harder domestically to argue that we shouldn’t sign the Amendment because people can then conduct advocacy and petition and lobby their States based on the fact that they’ve supported this tribunal.

But, on the other hand, maybe that’s the reason States don’t want to, or are reluctant, to sign up to this initiative to create a special tribunal. From my perspective, I think it’s still practically acceptable to move away from the ideal to say, let’s set up the tribunal and if States are concerned about this applying to them, then yes, perhaps we should silo it and make sure that this initiative is just Ukrainian focused and doesn’t have wider spill over effects on other national interests of States. But, of course, that doesn’t preclude or hinder the narrative change that would occur, the normative changes that would occur, from the creation of the tribunal being long term. That’s exactly the inherent tension there when it comes to trying to get support for this tribunal.