N-Arms Non-Proliferation Pact Made Permanent A Month Ago, Many U.N. Delegates Were Opposed To Allowing Only Five Nations To Keep Nuclear Weapons

More than 170 nations agreed on Thursday to extend in perpetuity a treaty that has limited the spread of nuclear arms for a quarter of a century.

The Treaty on the Non-Proliferation of Nuclear Weapons, a bedrock agreement in Soviet-American relations that arose in the midst of the Cold War, became permanent on Thursday by acclamation.

The original treaty, which went into effect in 1970, had to be reviewed this year, to decide whether it should be extended for a set period, ended, or prolonged indefinitely. The treaty basically limits nuclear weapons to the five states that had proclaimed them at the time - the United States, Britain, France, China, and the Soviet Union, now Russia. All other signers had to promise not to acquire them.

Thursday’s announcement followed four weeks of sometimes bitter debate between those five declared nuclear powers, all of whom favored indefinite extension, and nations without nuclear arms, many of which were just emerging from colonialism when the treaty was written 25 years ago and were hesitant to see it extended in its present form indefinitely. They argued that the treaty had allowed a small number of countries to have a monopoly over nuclear arms and that these nations were not providing nuclear technology for peaceful uses to developing countries.

When the conference opened last month, the United States and its allies, among them Russia, faced formidable opposition to an indefinite and unconditional extension of the treaty, and did not have enough declared votes for a simple majority had there been a ballot, according to independent estimates.

Over the weeks, however, the opposition, led by larger developing nations - among them Mexico, Venezuela, Egypt, Nigeria, and Indonesia - began to split.

The eventual collapse of the opposition to an indefinite extension was hastened by the decision of South Africa to back such a plan and propose a package of confidence-building documents that would meet some of the concerns of the non-nuclear weapons nations. South Africa has said it abolished a nuclear weapons program, and signed the treaty in 1992.

That package became the basis for negotiations led by the conference’s president, Jayantha Dhanapala, a Sri Lanka diplomat, to find enough common ground for consensus on extending the treaty indefinitely.

In the last 48 hours, President Clinton personally campaigned for the indefinite extension, writing what a U.S. official called “tough messages” to Egypt and Mexico, emphasizing the importance of the issue to the United States.