India has won a significant victory in its efforts to claim an exception to rules designed to thwart the proliferation of nuclear weapons. Delhi did not accomplish this on its own: It got considerable help from Washington, which seeks to build a new relationship with the world's largest democracy.

However, strategic gains may have come at the expense of the global nonproliferation order. The Indian exception will encourage other countries to seek similar treatment, which will accelerate the unraveling of the Nuclear Nonproliferation Treaty (NPT).

India, like Pakistan and Israel, has long objected to the NPT, arguing that the treaty's distinction between nuclear and nonnuclear weapons states is a form of discrimination. Delhi never signed the treaty and has remained committed to the development of its own nuclear arsenal, for reasons of national defense and international status. It tested its first "peaceful nuclear explosion" in 1974 and weapons-related devices in 1998.

Delhi's determination to maintain the nuclear option put it outside the global nonproliferation regime, cutting itself off from access to nuclear technology and fuel. As part of the nonproliferation effort, holders of nuclear technology formed the Nuclear Suppliers Group (NSG), which now includes 45 member states, to create rules to ensure that such technology and materials do not get into the wrong hands, including India's.

Meanwhile, the administration of U.S. President George W. Bush sought to develop a new relationship with India, one that linked the common interests of two of the world's largest democracies. Central to the creation of this new relationship was to soothe tensions created by U.S. opposition to India's nuclear ambitions. Thus the two governments negotiated a civilian nuclear cooperation agreement that would put 14 of India's 22 nuclear reactors under international safeguards. Ultimately, however, the two countries needed the other members of the NSG to approve the deal, which was accomplished Sept. 6.

For some, this was a historic breakthrough that brought a persistent objector into the global nonproliferation regime. In addition, it will help India develop alternative energy sources for its rapidly developing economy — thereby diminishing demand for oil — and help cut greenhouse-gas emissions. India is now one of the world's top five sources of such gases.

For others, however, the deal carves out an Indian exception that lets Delhi keep significant parts of its nuclear program away from prying eyes, and trades formal comprehensive safeguards for political promises. It is, reports one nonproliferation advocacy group, "a nonproliferation disaster of historic proportions that will produce harm for decades to come."

The NSG operates by consensus and, by all accounts, a meeting of the minds was not easy to achieve. The discussions stretched beyond the deadline in the original schedule, and agreement was reached only after considerable behind-the- scenes pressure by U.S. Secretary of State Condoleezza Rice. She is said to have made two dozen phone calls to world leaders; Mr. Bush weighed in as well.

Key objections concerned the group's response to evidence that India was not meeting its nonproliferation and disarmament commitments. In short, what would happen if India tested another nuclear device? India has not signed the Comprehensive Test Ban Treaty, and since it is not a signatory to the NPT, it has made no legal commitment to disarmament (unlike other nuclear weapons states).

In a statement issued with the announcement of the NSG agreement, Japan said it participated in granting the exemption on the condition that India continues to observe its commitments, especially its nuclear test moratorium pledge. If India resumes testing, "the logical consequence is to terminate trade." Most other countries made the same point in their own statements. U.S. law requires a suspension of nuclear trade with a country that conducts nuclear tests. That makes sense, but Indian leaders have told their public and Parliament that the deal imposes no restrictions on their behavior.

India has a good proliferation record. There is no evidence that it has facilitated the spread of nuclear technology or knowhow to other countries. But by allowing NSG members to sell nuclear fuel to India, the agreement frees up the country's limited domestic uranium supplies for its weapons program.

Most worrisome, the deal sets a bad example. An exception for India will encourage Pakistan, North Korea, Iran and who knows who else to seek similar treatment. India may claim to be unique with an exemplary record and unique circumstances, but all governments will now be encouraged to make that claim as well. It is a dark day for the Nuclear Nonproliferation Treaty and hopes for a nuclear-weapons free world.