LOS ANGELES: The revelation that North Korea has pursued an active nuclear arms program vividly illustrates the precarious foundations of the Nuclear Nonproliferation Treaty. The rest of the world will not forever forgo nuclear weapons if the United States insists on forever retaining nuclear weapons.

Few Americans know that the U.S. government committed to eliminate the entire U.S. nuclear arsenal when the Nonproliferation Treaty came into effect 32 years ago. "The Nonproliferation Treaty does not simply aim to maintain the nuclear status quo," George Bunn, who served on the original U.S. negotiating team, said last spring. Article VI "requires that the original five nuclear weapon states pursue effective nuclear disarmament measures."

At the heart of the Nonproliferation Treaty is a grand bargain, whereby the nonnuclear weapons states agreed never to acquire nuclear arsenals, in exchange for the nuclear weapon states agreeing eventually to get rid of theirs.

Moreover, the nuclear weapon states - pushed hard by a group of middle powers known as the "New Agenda" countries - recommitted themselves to this goal at the 30-year Nonproliferation Treaty Review Conference in spring 2000. The conference's final statement, signed and agreed to by Washington, pledged "an unequivocal undertaking by the nuclear weapon states to accomplish the total elimination of their nuclear arsenals."

But the Bush administration's Nuclear Posture Review, released this year, indicates a clear intent to maintain a colossal nuclear arsenal for time without end. It lays out elaborate plans for designing and developing new generations of nuclear weapons for air, sea, and land deployment in 2020, 2030, and 2040. It does not name a date for any "unequivocal undertaking" on abolition.

The New Agenda countries expressed their astonishment over the audacity of the Nuclear Posture review in a joint statement just a few months ago. "Any presumption of the indefinite possession of nuclear weapons by the nuclear weapon states," they said, "is incompatible with the integrity and sustainability of the nuclear nonproliferation regime."

Why does this matter? Why should the United States bother to keep its word? Because the longer America insists on holding on to its own nuclear arsenal, the more likely it becomes that others will acquire nuclear arsenals of their own.

When the United States insists that nuclear weapons are vital to its own security but harmful to the security of others, it becomes hopelessly lacking in credibility.

If North Korea does in fact already possess nuclear warheads, as Defense Secretary Donald Rumsfeld said Thursday, that makes nine nuclear weapon states. Can there be any greater threat to human security than the possibility of a world with 10 or 20 or 30 nuclear weapon states? If that world comes to pass, some kind of nuclear conflagration - perhaps by an accidental or unauthorized launch, perhaps at the hands of a nuclear terrorist, perhaps by leadership miscalculation in a hot political crisis - will become inevitable.

If anything seems preordained about the political landscape of the future, it is that humanity will eventually have to choose between a world of dozens of nuclear weapon states or a world of zero nuclear weapon states. A world with a few "nuclear haves" and a great many "nuclear have-nots" cannot forever endure.