As the world community watches Russia pummel Ukraine, there are increasingly loud calls for justice. Those calls have largely focused attention on the key decision-maker in this drama: Vladimir Putin. Western governments have applied the term “war criminal” to Putin, and President Joe Biden, supposedly speaking off-script, exasperatedly quipped at the end of a 27-minute address, “For God’s sake, this man cannot remain in power.” As rumors circulate that there is a price on Ukrainian President Volodymyr Zelensky’s head, a growing number of voices have even called for the assassination of the Russian president.

This is a moment to stop and take a breath. When we bandy about “war crimes,” “assassination,” and other terms, we ought to consider what we are talking about and, if appropriate, what the available mechanisms for justice are.

First, the West should not engage in any effort to assassinate Vladimir Putin. There is a longstanding prohibition on attacking political leaders in so-called “decapitation strikes.” There may be very rare instances when these are justified, but in general they are unwise. Wiping out senior leadership erodes order. Such an attack is not truly an effort at justice, but rather a strategic assault that could unleash unexpected forces of chaos. World War I began with an assassination, and in other moments, such as Julius Caesar’s assassination, killing a leader did not result in peace or a new republican form of government, but instead civil war and ultimately a new strongman.

What about Diedrich Bonhoeffer? It is noteworthy that Germans, not assassins on direct orders by Franklin Roosevelt or Winston Churchill, made the attempt on Adolf Hitler’s life.

That takes us back to the “war crimes” language we have been hearing. I would like to introduce a framework for thinking about these injustices and the usual mechanisms for prosecuting them. These methods are more likely to punish Vladimir Putin and his henchmen.

First, following World War II, the Nuremberg Trials underscored three types of war criminality. The first is crimes against peace, meaning the planning and initiation of war. Later, the Rome Statute, which authorizes the International Criminal Court (1998), uses the language “crimes of aggression” for the same activities, noting they “constitute a manifest violation of the Charter of the United Nations.” The second type of war criminality is violations of the law of armed conflict: war crimes. This includes violations of the just war categories of proportionality and discrimination, such as targeting civilians, apartment buildings, and the like. The third Nuremberg category is crimes against humanity, which includes the terrible elements of the Holocaust: “murder, extermination, enslavement, deportation, and other inhumane acts committed against any civilian population… persecutions on political, racial, or religious grounds in execution of or in connection with any crime within [this] jurisdiction.” The Rome Statute distinguishes “crimes against humanity,” such as enslavement and ethnic cleansing, from full-scale genocide (extermination of a people group), which is defined in the 1949 Genocide Convention.

These categories help us narrow our thinking. Clearly, Russia’s invasion is a crime against peace, a crime of aggression. That is a charge to be leveled at Russia’s leadership. Second, the systematic, brazen attacks on Ukraine’s civilian population, such as in Mariupol, are war crimes. However, it is unlikely that a case can be made at this point for crimes against humanity or genocide.

With the categories in mind, what are the mechanisms for justice? At the end of World War II, the victorious Allies set up the Nuremberg Trials and parallel trials in Japan (Tokyo Trials). These were unprecedented as there had been no similar military tribunals on this scale in the past, although there had been earlier attempts, such as the stillborn Leipzig Trials following the First World War. They were also a key development of a new, liberal international order that included Universal Declaration of Human Rights as well as the United Nations and other institutions. These post-war years also gave us the Genocide Convention and the revised 1949 Geneva Conventions—which protected the wounded, shipwrecked, prisoners of war, and others. All of these developments were needed due to the fact that the Axis Powers had not just attacked their neighbors, but through their demonic ideologies and destructive policies, they attacked the moral and legal foundations of civilization.

Now the UN Security Council may set up special tribunals that are, in a sense, the direct descendants of Nuremberg. These are extremely rare, the two notable examples being international tribunals for the former Yugoslavia and Rwanda. Both cases could go forward, in part, due to the extreme depravity of the killings there and due to the changed global context. The Cold War was over, and there was greater political international will to act.

There is a separate International Court of Justice, and Ukraine has made an allegation before it that the current conflict is a case of genocide against the Ukrainian people. The ICJ is an organ of the United Nations, and its primary mandate is to adjudicate between member governments. It can also render legal opinions on matters that come to the ICJ from other UN agencies.

Finally, there is the International Criminal Court, noted above. The 1999 Rome Statute created this body in the aftermath of Yugoslavia and Rwanda. It has been a forum for accusing some bloodthirsty villains, such as Joseph Kony of the Lord’s Resistance Army, of crimes against humanity. Although most countries have signed the charter to join the ICC, major powers such as the United States, Russia, and China have not, and therefore are not technically under its jurisdiction. There is a mechanism by which non-members may be hauled before the ICC: referral by the UN Security Council. That is extremely unlikely for obvious reasons.

To this point, I’ve tried to describe the basic framing of war criminality and illustrate the three usual mechanisms that diplomats, humanitarians, and international legal experts look to. It is hard to imagine the UN Security Council or Moscow authorizing a meaningful new war tribunal on the model of Rwanda and Yugoslavia, a referral to the ICJ, or an indictment before the ICC.

That does not mean that war crimes are not occurring. It does not mean that actors cannot seek punition. Also, it does not mean that extra-judicial means, such as assassination, should be employed.

Instead, we should think about the best mechanisms for narrowly punishing wrong-doers, especially the leaders who launched this war and manage its day-to-day activities. Second, over time, we are going to need to find mechanisms for restitution for the victims.

As we focus on punishment, first, don’t forget that the on-the-ground war must be won. Ukrainians are fighting, and they need all of the military technology and armaments that can be provided. Give them the tools, Zelensky begs. They are showing us true grit in the fight.

Second, what is most likely to hit Putin and his oligarchy of supporters are financial attacks. The most meaningful punishment possible is likely drying up Putin’s access to further resources, and Western powers taxing or liquidating his assets. There are mechanisms, such as under the Magnitsky Act, for continuing to hammer away at the hundreds of billions of dollars of private wealth that Putin and his cronies hold. Moreover, there may be a change in political climate in the future that would allow other forms of prosecution against Putin.

What we do not want, at present, is to make Putin a martyr or harden Russian resolve. The battle against Putin must be waged against him, his kleptocratic buddies, and the Russian military in the field and not the Russian citizenry at home. It may be the case that Putin, long popular with at least a plurality of his population, has overplayed his hand and will go down at the hands of his own people, whether at the polls or in some other fashion. This course of action is most consonant with the principles of long-term regional order and justice. And, now, we must look ahead and imagine the conditions for conciliation.