DURHAM, NORTH CAROLINA — Making war, traditionally a prerogative of presidents and princes, may soon become an international crime.

The states that have signed on to the International Criminal Court are on the cusp of adding “aggression” to that list of crimes that it is empowered to prosecute, alongside genocide, crimes against humanity and war crimes. It would be a game-changer in international diplomacy, but it carries great risk along with its promise.

The idea of prosecuting a country’s leader for ordering a war that violates the United Nations Charter is appealing, until you imagine your own leader in the dock for a war that your countrymen all accepted as self-defense or humanitarian intervention. Just as one nation’s terrorist is another nation’s freedom fighter, one state’s just war is bound to be another state’s unjust war.

Nonetheless, after a decade of negotiations, and against all expectations, the Assembly of States Parties to the I.C.C. has produced a draft.

When asked, many diplomatic delegations explain the draft as the natural culmination of the legacy of the Nuremberg Trials, where Hermann Göring and other top Nazis were prosecuted by an international tribunal for planning, preparing, initiating and waging aggressive war against their neighbors.

The Nuremberg tribunal found Göring and 11 others guilty of what was then known as the “crime against peace,” famously declaring: “To initiate a war of aggression, therefore, is not only an international crime; it is the supreme international crime differing only from other war crimes in that it contains within itself the accumulated evil of the whole.”

Unfortunately, plans by the newly formed United Nations to create an international criminal court with jurisdiction over aggression were sidelined during the Cold War because the United States and Soviet Union couldn’t agree on an enforceable definition.

Now that the Cold War is over, is the Nuremberg precedent still relevant?

The acts that amount to aggression in the I.C.C. definition are familiar to any student of World War II: invasion, bombardment, blockade, attacking the armed forces of another state, contravening an agreement to station forces in another state, allowing one’s territory to be used by another state to attack a third state, and the sending of armed bands. Saddam Hussein’s invasion of Kuwait in 1990 is a textbook act of aggression.

To be on the safe side, the drafters have deliberately defined aggression more narrowly than does customary international law. Under the I.C.C. definition, an enforceable crime of aggression would only capture the most egregious violations of the U.N. Charter, leaving out — to the consternation of many pacifists — leaders implicated in “gray-area” interventions. One example that many of the drafters had in mind was the NATO intervention to prevent ethnic cleansing by Slobodan Milosevic’s forces in Kosovo.

Still, skeptics abound. In a recent speech to the American Society of International Law, Harold Koh, the Yale Law School dean who is currently legal adviser to the U.S. State Department, said, “if you think of the [International Criminal] Court as a wobbly bicycle that is finally starting to move forward, is this frankly more weight than the bicycle can bear?” Koh’s concern is that adopting a definition of something as subjective as aggression could politicize and weaken the young institution.

Michael Glennon, professor of international law at the Fletcher School at Tufts University, warned on these pages (April 6) that implementing the definition will “bollix an international equilibrium that already is precarious enough.” His concern, which I share in part, is that criminal prosecution of aggression could serve to increase political tensions, harden positions and undermine alternative avenues to ending conflicts, such as negotiated solutions.

The drafters respond that there can be no sustainable peace while leaders such as Sudanese President Omar al-Bashir commit crimes against their own and neighboring populations with impunity. They point to peaceful transitions in Serbia and Liberia following the arrest of Slobodan Milosevic and Charles Taylor for other international crimes. The lesson they draw is that bullies should be politically isolated, arrested and held to account — not appeased.

The drafters reject as a false distinction Koh’s position that aggression is fundamentally different from the three currently enforceable I.C.C. crimes — genocide, crimes against humanity and war crimes — because aggression is based on acts committed by a state while the others are crimes directed against particular individuals.

All four international crimes are collective acts of violence, they reply, attributable to political or military leaders against vulnerable individuals. In the case of aggression, the primary victims are the innocent people killed in a war that violates the U.N. Charter.

My hope, along with the drafters, is that individual criminal responsibility for the illegal use of armed force will make international law more credible and will supplant the existing system of collective guilt, whereby populations are sanctioned for the decisions of their delinquent leaders.

It was the Iraqi population, not Saddam’s inner circle, who really suffered under U.N. sanctions after Saddam illegally invaded Kuwait.

Criminal accountability will not end war, but it may change the broader rules of domestic and international politics so that war is no longer such a tempting option.

Had aggression been a prosecutable crime in 2003, Prime Minister Tony Blair — who relied heavily on the legal advice of his attorney general — may have never brought his country to war in Iraq without a Security Council resolution authorizing him to do so.

Along with the skeptics, however, I’m wary of victor’s justice. It is one thing to prosecute a defeated warlord and quite another to arrest the victorious leader of a powerful and modern state. But even victors are liable to prosecution — witness Milosevic and Taylor.

The drafters’ challenge is to temper justice with prudence when they meet in Kampala in June to activate the crime.

A reasonable compromise, in my opinion, is to limit I.C.C. jurisdiction over aggression to states that sign on to the new prohibition, thereby creating a regime of states committed to the prosecution and enforcement of the crime.

What would be lost, at least in the short-term, is the notion of perfect justice universally applicable to political and military leaders worldwide. But what is gained is an incremental shift toward the rule of law in international affairs that may, over time, become the norm.