Philadelphia ? Last week, President Bush effectively “unsigned” a treaty committing the United States to participation in the International Criminal Court, which is due to convene for the first time this summer.

On its face, the decision not to cooperate with other nations in an effort to punish genocide and war crimes seems indefensible. The move prompted immediate and predictable outrage internationally, particularly given the Bush administration’s record so far on world agreements most noticeably its withdrawal from the Kyoto Accords on global warming and its announced intention to ignore the Geneva Accords in its treatment of Taliban and al-Qaida captives.

“You have several important topics where we are getting these quite disquieting messages,” said Inocencio Felix Llamas Arias, Spain’s ambassador to the United Nations. “The perception in Chile, in Morocco, in India, in Finland, in Spain is that this is unilateralism, and people don’t understand why the leader of the whole world would be embracing unilateralism.”

It is also a setback for many well-intentioned jurists determined to create institutions to deter the wholesale bloodletting of innocents that typified the 20th century.

“I think it is a very backwards step,” said Judge Richard Goldstone, a South African who was the first chief prosecutor at the war crimes tribunal set up to deal with the war in the former Yugoslavia. ” The U.S. have really isolated themselves and are putting themselves into bed with the likes of China, Yemen, and other undemocratic countries.”

The International Criminal Court, which will sit in the Dutch city of the Hague, will be the first permanent court established to investigate and prosecute war crimes, genocide and other “crimes against humanity.” It will have jurisdiction over crimes committed after July 1, when it will formally convene. The treaty creating it was signed by 138 states and has been ratified by 66, which is sufficient to put it into effect. It is primarily supported by member states of the European Union, all of which have ratified it (except Greece, which is expected to do so next month).

Criticism of Bush’s decision is understandable. The United States is the world’s strongest military and economic power. Other nations rely on that muscle at the same time they fear it. To the extent that we submit to international cooperation, we relinquish a measure of our freedom to act unilaterally, if only in lending other participating nations moral leverage.

A longing for global justice and peace gives the idea of world courts and world government a strong pull, but President Bush is right to tread cautiously. Our rights and legal protections are a hard-won legacy, the product of centuries of national struggle and sacrifice. They have set a standard for the world. Before we hand them over to any world authority, no matter how appealing it may be in principle, we need to make certain that we are not simply throwing them away.

Even former President Bill Clinton, who signed the treaty three weeks before leaving office but did not submit it to Congress for ratification, has said that he did not support the treaty in its current form.

Ratifying it would have meant ceding a piece of national sovereignty to an international body with no track record and with rules of procedure that would not guarantee U.S. citizens the full protection of our Constitution. Because the United States is most often called upon to act militarily, it would put American soldiers and political leaders particularly at risk; one man’s war on terrorism is another man’s war crime.

Proponents of the treaty argue that the court is meant to “complement” existing national criminal justice systems, not replace them. But if member states can avoid the court’s jurisdiction by conducting bogus investigations or show trials, the court will serve no purpose. The treaty’s preamble specifies that the international court will step in only if member nations fail to investigate or prosecute alleged crimes themselves, or if they fail to do so “effectively.” Who would determine ineffectiveness?

Member nations would, which boils down ultimately to politics. No matter how many safeguards are in place, for the court to function effectively it needs the authority to act over the objections of member nations. That means, at heart, that member states must agree to submit to some extent to the court’s sovereignty. So while the idea of such a court is appealing, it does not come without a cost.

This will be one of the critical issues of the 21st century. To what extent are individual nations willing to give up pieces of their sovereignty in order to further the cause of world justice and peace? For Americans, who live under one of the most liberal systems on the planet, our concern should be that any such move guarantees the rights and liberties of our Constitution.

It reminds me of the parable told in the famous “Twilight Zone” episode in which earthlings are lured into enthusiastic cooperation with seemingly well-intentioned aliens. Skeptics are won over when code-breakers translate the title of an alien manual, “To Serve Man.” It turns out to be a cookbook.