On Monday evening, in prepared remarks at a conference in Washington D.C., U.S. Ambassador for Global Criminal Justice, Beth Van Schaack made a significant announcement: “[T]he United States supports the development of an internationalized tribunal dedicated to prosecuting the crime of aggression against Ukraine.”

This clear statement of U.S. support for a prosecution of aggression merits a moment of celebration, even though there are plenty of caveats that come with that laudatory response. When Ryan Goodman and I first published a model indictment of Putin for the crime of aggression this time last year, the possibility of the United States doing anything but stonewalling an aggression prosecution seemed remote. The through line of the U.S. government’s approach to this issue has long been one of skepticism, with successive administrations seeking to retain judgment regarding aggression within the province of the UN Security Council. Few who have been involved in U.S. negotiations on the crime of aggression over the years would have forecast Monday’s statement. Credit is due to Ambassador Van Schaack, her team, and other supporters of accountability for aggression within the Biden administration for what would undoubtedly have been many rounds of interagency negotiations to get to this point.

Here though, come the caveats. Ambassador Van Schaack’s statement went on to characterize the tribunal the United States supports as being “an internationalized national court” (emphasis added). She described it as a tribunal “rooted in Ukraine’s judicial system, but that also includes international elements.” There is a lot of room for interpretation within that description, though it seems to echo the proposal supported by the U.K earlier this year for a “hybrid” tribunal. 

Just Security has given comprehensive coverage to the various models that have been proposed for an aggression tribunal. Many experts believe that an agreement between Ukraine and the United Nations, on recommendation of the UN General Assembly, would give an aggression tribunal an optimal legal foundation. Others in these pages have advocated for an amendment to the International Criminal Court’s statute. There are yet other options akin to the Special Court for Sierra Leone, that while sometimes described as “hybrid” would be significantly more international than the model the United States is apparently now supporting. 

Meanwhile, the downsides of anything short of a truly international tribunal are significant. A tribunal that is a national court of Ukraine, no matter how international its “elements” may be, poses at least two challenges that could be fatal to the endeavor. First, the creation of such a hybrid court is likely unconstitutional under Ukrainian law. Article 125 of the Ukrainian Constitution contains an outright prohibition on “special and extraordinary tribunals.” An article by Alexander Komarov and Oona Hathaway provides the details, but in sum, anything less than an international tribunal is likely to pose a constitutional challenge. Could a sufficiently motivated Ukrainian government find a way to creatively lawyer around this hurdle? Maybe. But as Komarov and Hathaway explain, the Constitution bans constitutional amendments under conditions of martial law or a state of emergency. Even if some creative lawyering approach somehow succeeded and on a workable timeframe, it could undermine the commitment to the rule of law that undergirds the legitimacy of any such project. 

Second, a hybrid tribunal will run directly into the head of state immunity problems that have been an integral part of all proposed tribunal discussions to date. Of course, head of state immunity would likely need to be litigated in any forum that sought to prosecute Putin (or his Foreign or Defense Ministers, should they stand accused), and some question whether even a fully international tribunal could overcome immunity ratione personae (former State Department Legal Adviser Harold Hongju Koh noted in the New York Times on Tuesday that “even under a purely international model, the issue of overcoming immunity for sitting heads of state is far from assured”). However, there are far more compelling arguments that an international tribunal would pierce the veil on head of state immunity (see Jennifer Trahan’s commentary on this for a full analysis). In other words, for as long as Putin remains in office, only an international tribunal, and not the kind of tribunal that the U.S. supports, has a shot at prosecuting him. And Putin is, of course, the most responsible for the very crime any such tribunal is supposed to prosecute.

The most charitable account of the U.S. and U.K. stance is to say that even an international tribunal would be unlikely under any circumstance to be able to apprehend Putin – or other troika-level officials with immunity ratione personae – as long as Putin remains in office. On this account, the question of whether an aggression tribunal can overcome head of state immunity is, for practical purposes, a moot point. Or at least, it is a factor that should not dissuade advocates of accountability from pursuing a hybrid tribunal if that is the most politically feasible option on the table.

On the issue of political feasibility, supporting an option that avoids having to secure buy-in from the UN General Assembly might be seen as a safer bet for accountability. Right now, the March 2022 UNGA resolution condemning Russian aggression in Ukraine provides a strong expressive message against Putin and Russia’s predation. One may fear that seeking a UNGA resolution on an aggression tribunal, and then failing to get enough support (or getting just a bare and geopolitically skewed margin of support) would detract from the high watermark of near-global condemnation that the March 2022 resolution provided.

And yet.

Aggression is fundamentally a leadership crime. Ukrainian officials have been adamant from the outset of the aggression tribunal conversations that they want to see Putin held to account for the war that he is uniquely responsible for unleashing on their country. More fundamentally, political feasibility is always as much constructed as it is given. Perhaps at this moment, it feels like a stretch to secure the necessary two thirds of those present and voting for an aggression tribunal at the UN General Assembly. But if the United States committed to the effort, that which seems unlikely today may well be possible tomorrow.  

If the most charitable account of the decision to support an “internationalized national court” is that it is politically feasible, then the question becomes: Is the politically feasible option better than nothing? Reasonable minds will certainly differ on this. At a minimum though, anyone supporting the U.S. and U.K. approach should be concerned about the inevitable specter of officials many levels below Putin being prosecuted for a crime for which he bears ultimate responsibility. And if Putin remains free while lower-level officials are convicted, the entire effort could have a delegitimizing effect on accountability for aggression. 

The issue of precedent

Stepping back from the specifics of the Ukraine case, the inter-agency debates behind Monday’s announcement must surely have worked through the question of what precedent support for an aggression tribunal would set. “Ms. Van Schaack acknowledged its reluctance to create a precedent that could pave the way for a similar court to prosecute American leaders,” the New York Times’ Glenn Thrush and Charlie Savage reported. The United States has never been comfortable with the idea of an international tribunal adjudicating its actions. Indeed, even in some future world in which the United States joined the International Criminal Court, it is impossible to imagine that it would sign onto the Court’s aggression provisions. From this perspective, the United States may seek to thwart the emergence of an international tribunal that could potentially be repurposed or expanded to pursue future cases of aggression perpetrated by other states (the United States included). But if those inside the U.S. government believe that by instead supporting an “internationalized national court” in Ukraine they are somehow limiting the replicability or generalizability of the effort, they are mistaken.

The precedent being established here is that any state that is a victim of aggression – or, in a future scenario, merely perceives itself to be a victim of aggression – can, with the support of allied states, create an internationalized national court to prosecute its (actual or perceived) aggressor. Unlike a truly international tribunal, an “internationalized national court” is endlessly replicable; it requires one aggrieved state and some minimum number of supporting states.

The Pentagon believes (erroneously) that sharing evidence of Russian war crimes to the ICC is not worth the risk it brings to its own personnel. Yet the precedent about to be set here presents at least as much risk to the U.S. military going forward. It may be counterintuitive, but putting in the diplomatic legwork to secure UN General Assembly support for a truly international tribunal is the approach that both meets the laudable bipartisan U.S. commitment to accountability for Russian aggression and limits the exposure risks that may well have driven an interagency process to reach this least-best tribunal option in the first place. 

In her remarks on Monday evening, Ambassador Van Schaack emphasized that “we are at a historic moment for international criminal justice.” Surely this moment, with bipartisan support to achieve accountability for Russia’s invasion of Ukraine, merits the wholehearted pursuit of the first-best option for prosecuting the architect of the entire war.

IMAGE: From left, Ambassador-at-Large for Global Criminal Justice Beth Van Schaack, State Department interim spokesman Vedant Patel, Acting Assistant Secretary, Bureau of Democracy, Human Rights, and Labor, and Coordinator for Global Democratic Renewal Under Secretary for Civilian Security, Democracy, and Human Rights Erin Barclay, listens as Secretary of State Antony Blinken speaks at a briefing on the 2022 Country Reports on Human Rights Practices at the State Department in Washington, Monday, March 20, 2023. (AP Photo/Andrew Harnik)