Today, a day after America memorialized once again the terrible events of Sept. 11, 2001, hundreds of ordinary citizens will embrace the only useful lesson of that fateful day: the common world's ever more common destiny.

They will celebrate the first Interdependence Day in Philadelphia, as well as in Budapest, Hungary, and on a number of university campuses. In promulgating a new "Declaration of Interdependence," they will both honor the historic journey whose end 9/11 cruelly announced and embark on a new journey 9/11 made ineluctable.

Two hundred and twenty-seven years ago, in the belief that liberty and the autonomy of the sovereign nation went hand in hand, America proclaimed its independence. For more than two centuries it has pursued sovereignty as the basis of the rights and social justice in whose name it has striven to become both democratic and free. Speaking not just for itself but for other nations, it has (as President Bush did again in his Sunday night speech on terrorism) insisted that democracy is premised on national liberation and that personal liberty requires national independence.

Yet nations that have long cherished their independence, or recently struggled to achieve it, are learning the hard way that there is neither freedom nor equality nor safety from tyranny - nor security from terror - on the basis of independence alone. In a world in which ecology, public health, markets, technology, and war affect everyone equally, interdependence is a stark reality on which the survival of the human race depends. Where fear rules, and terrorism is met by shock and awe only, neither peace nor democracy can ensue.

We have not yet constructed global institutions that might offer us a benevolent interdependence - but we are beset by forces that, in malevolent and anarchic ways, force interdependence on us. If we do not democratize our interdependence, we may lose the blessings conferred by the old journey to democratic independence.

Where once nations depended on sovereignty alone to secure their destinies, today they depend on one another. In a world where the poverty of some imperils the wealth of others, where none are safer than the least safe, multilateralism is not a stratagem of idealists but a realistic necessity. The lesson of 9/11 was not that rogue states could be unilaterally preempted and vanquished by a sovereign United States, but that sovereignty was a chimera - that HIV and global warming and international trade and nuclear proliferation and transnational crime and predatory capital had already stolen from America the substance of its cherished sovereignty well before the terrorists displayed their murderous contempt for it on that fateful morning.

America still hopes to play the Lone Ranger in a world where in truth only global posses have a chance of succeeding. For interdependence is now our reality - and the acknowledgment of interdependence is the necessary starting point for prudent foreign policy.

But citizens need not wait for presidents or governments to embrace interdependence. The simple fact is that no American child will ever again sleep safely in her bed if children in Baghdad or Karachi or Nairobi are not secure in theirs.

Today, the journey from independence to interdependence begins for those gathering in Philadelphia and Budapest to pledge themselves citizens of one world, "civic, civil and civilized... recognizing [their] responsibilities to the common goods and liberties of humankind as a whole." They will be pioneers on a journey on which every citizen, postman and president alike, must in time embark.

Benjamin R. Barber is the Gershon and Carol Kekst Professor of Civil Society at the University of Maryland and a principal of the Democracy Collaborative. He is author of "Jihad vs. McWorld" and "Fear's Empire: Terrorism, War and Democracy."

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