NEW YORK This month the first assembly of states supporting the International Criminal Court convened at United Nations headquarters in New York. This new milestone in the march toward a tribunal for the world's worst human rights criminals was a moment of celebration. But the festivities were marred by the latest assault of the United States on the court.

The dispute is part of Washington's long-standing efforts to exempt U.S. citizens from the reach of the ICC. Nominally it concerns how to interpret Article 98 of the Rome treaty establishing the court, but in fact the court's legitimacy is at stake. Article 98 recognizes agreements among ICC member states to resolve competing claims to prosecute a suspect. For example, if government A sends a soldier to country B where he commits a war crime, both governments A and B would have a legitimate interest in prosecution. Article 98 permits them to enter into an agreement ordering their claims - to decide which prosecution would take priority. The Rome treaty requires the ICC to defer to the resulting national court process, assuming that it is conducted in good faith.

But if agreements under Article 98 are to remain true to the purpose of the Rome treaty, they must respect the ICC's right to intervene in national prosecutions should they prove to be a charade. No ICC suspect should ever be sent under Article 98 to a government that does not recognize this right.

The Bush administration rejects any ICC oversight, but it still seeks agreements with governments to send any American suspect to the United States rather than to the ICC. That effort to circumvent the Rome treaty should be rejected.

Some European governments are suggesting that Washington's proposal would be acceptable if the Bush administration made a "no impunity" pledge - that is, if it vowed to investigate and, if appropriate, prosecute any suspect sent its way. But that would be no more than a fig leaf to disguise this effort to undermine the ICC's oversight function.

The entire point of the ICC was never to trust unverified national pledges to bring the worst hu- man rights criminals to justice. A regime of unverified national pledges is what ensured that Augusto Pinochet, Idi Amin and Pol Pot were never properly tried. Without an ICC scrutinizing those pledges, there is nothing to prevent the use of political influence, intimidation or violence to compromise national efforts to prosecute.

Recognizing this fact would require Washington to accept ICC oversight whenever a government that has ratified the Rome treaty sends an ICC suspect to the United States.

Today many governments refuse to extradite murder suspects to the United States unless Washington agrees to forsake the death penalty, a condition that America reluctantly but routinely accepts. Similarly, no ICC suspect should be sent to the United States unless Washington recognizes the jurisdiction of the ICC to intercede in that case in the event of a sham investigation or prosecution. At bottom, the dispute is not about the unlikely possibility that American soldiers will find themselves in the dock. It is about the legitimacy of the ICC. As the Bush administration is fully aware, a court that exempts the world's superpower risks losing its legitimacy.

Indeed, that is the goal of certain extremists in Washington who seek to exercise America's unprecedented military power without the inconvenient constraints of international law, or at least international law enforced by anyone other than the United States itself.

We stand today on the threshold of a new era in international law enforcement because so many nations of the world banded together in defense of principle. Similar collective action is needed to defeat new challenges to the scope and legitimacy of the ICC. Nations of the world have every right to insist on recognition of a basic principle: Whenever someone, even a soldier of the superpower, commits an atrocity on their territory, they are obligated to enlist the ICC to ensure prosecution.

Without U.S. acceptance of that principle, the agreements Washington seeks under the guise of Article 98 should be rejected as impunity deals that are inconsistent with the purpose of the Rome treaty.