THE UNITED States has an important national interest in strengthening relations with India and making it a strategic partner in the 21st century. But efforts to cement ties with India should not be pursued in a way that undermines a U.S. national interest of equal or arguably greater importance: preventing the proliferation of nuclear weapons. The Bush Administration has made precisely that mistake in the nuclear deal reached this past summer during Prime Minister Manmohan Singh's visit to Washington.

In the joint statement released on July 18, India agreed to take several steps to demonstrate its commitment to being a responsible nuclear power and supporter of non-proliferation goals. In exchange, the administration agreed to seek changes in U.S. law and multilateral commitments to permit exports of nuclear equipment and technology to India--a radical departure from longstanding legal obligations and policies that precluded nuclear cooperation with states not party to the Nuclear Non-Proliferation Treaty (NPT).

Administration officials have claimed that by aligning India more closely with the policies and practices of the international non-proliferation regime, the deal achieves a net gain for non-proliferation. Several of the steps pledged by India are simply reaffirmations of existing positions--for example, continuing its moratorium on nuclear testing, strengthening export controls and supporting negotiations on a multilateral fissile-material cutoff treaty. Some other steps are indeed new and useful. Among these are the commitments to place civil nuclear facilities under International Atomic Energy Agency (IAEA) safeguards and to refrain from transferring enrichment and reprocessing technologies to states that do not already possess them.

Still, the non-proliferation gains of the deal are meager compared to the major damage to non-proliferation goals that will result if the deal goes forward as it currently stands.

The U.S.-Indian deal would make it harder to achieve key Bush Administration non-proliferation initiatives. The United States is now asking the 45-nation Nuclear Suppliers Group (NSG) to permit nuclear cooperation only with countries that adhere to the IAEA's Additional Protocol and to ban transfers of enrichment and reprocessing technologies to states that do not already possess fuel-cycle facilities. But getting NSG partners to tighten the rules in ways favored by the United States will be an uphill battle if they are also being asked to bend one of their cardinal rules (that is, no nuclear trade with non-parties to the NPT) because it no longer suits the United States.

By seeking an exception to the rules to accommodate America's new friendship with India, the deal reinforces the impression that the U.S. approach to non-proliferation has become selective and self-serving, not consistent and principled. Rules the United States initiated and championed would be perceived as less binding and more optional. Countries with good relations with Washington may conclude that the United States will tolerate and eventually accommodate a decision to acquire nuclear weapons, while China and Russia may feel less inhibited about engaging in nuclear cooperation with "special friends" of their own that the United States might find risky and objectionable.

The nuclear deal in its present form has produced resentment on the part of close U.S. partners like Japan, Germany and Brazil who were forced to choose between nuclear weapons and civil nuclear cooperation. They chose the latter, giving up the weapons option and joining the NPT to realize the benefits of nuclear cooperation. Now that India has been offered the opportunity to have its cake and eat it too, many non-nuclear NPT parties feel let down. Not wishing to harm relations with either India or the United States, they are unlikely to make a public fuss over the sudden reversal of U.S. policy (on which they were not consulted). But they will be less inclined in the future to make additional sacrifices in the name of non-proliferation.

Moreover, U.S. plans to engage in nuclear cooperation with India will make it more difficult to address proliferation challenges such as Iran. Of course, Iran's interest in nuclear weapons long predated the India deal. But the deal has strengthened the case Iran can make internationally. Why, Iranian officials have asked publicly, should Iran give up its right as an NPT party to an enrichment capability when India, a non-party to the NPT, can keep even its nuclear weapons and still benefit from nuclear cooperation?

In general, the Bush Administration's policy shift conveys the impression that the United States--the country to which the world has always looked as the leader in the global fight against proliferation--is now de-emphasizing non-proliferation and giving it a back seat to other foreign policy goals. Other countries can be expected to follow suit in assigning non-proliferation a lower priority relative to political and commercial considerations in their international dealings, and this will have negative long-term consequences for the international non-proliferation regime.

THE DAMAGE can be minimized--and the deal transformed from a net non-proliferation loss to a net non-proliferation gain--if several improvements are made in the course of implementing the July 18 joint statement (whether by the U.S. Congress in adopting new legislation, by the governments of India and the United States themselves, by the Nuclear Suppliers Group in modifying its guidelines or by a combination of these).

The most important improvement would be an Indian decision to stop producing fissile materials for nuclear weapons. India need not stop such production unilaterally, but as part of a multilateral moratorium pending completion of an international fissile-material cutoff treaty. A multilateral production halt would make a major contribution to fighting nuclear proliferation and nuclear terrorism by capping stocks of bomb-making materials worldwide, thereby making those stocks easier to secure against theft or seizure.

Without a moratorium on fissile-material production, the U.S.-Indian deal could actually facilitate the growth of India's nuclear weapons capability. India's indigenous uranium supplies are quite limited. Under current non-proliferation rules--with India unable to buy natural uranium on the world market--India must use those limited supplies for both civil power generation and nuclear weapons, and the trade-off will become increasingly painful. Under the new rules, India could satisfy the needs of the civil program through imports, freeing up domestic uranium supplies for the weapons program and permitting, if the Indian government so decided, a continuing and even major increase in bomb-making material. A production moratorium would preclude such an increase.

Indian Foreign Secretary Shyam Saran said in July that India "is willing to assume the same responsibilities and practices--no more and no less--as other nuclear states." It so happens that the five original nuclear weapon states (the United States, Russia, France, the UK and China) have all stopped producing fissile materials for nuclear weapons. Applying the "no more, no less" standard, it would be reasonable to ask India to join the others. India claims that it seeks only a "credible minimum deterrent capability." If that is the case, then perhaps it can soon decide that it has sufficient plutonium for its deterrence needs and can afford to forgo further production.

ANOTHER WAY to strengthen the July 18 agreement would be for India to assume a more active and constructive role in helping the United States address today's most acute proliferation challenges, especially the challenge posed by Iran. Given its desire to make Iran a long-term source of energy supplies, India has been reluctant to press Iran on its nuclear program. During a September visit to Tehran, Indian Foreign Minister Natwar Singh made public remarks supportive of Iran's position on the nuclear issue and critical of the approach taken by the United States. The remarks produced a sharp backlash from members of Congress across the political spectrum, including several strong supporters of India, who made clear that India's failure to side with the United States on the Iranian nuclear issue would jeopardize congressional support for the legislative changes needed to implement the U.S.-Indian nuclear deal.

In response to these congressional warnings and tough messages conveyed in person by President Bush and Secretary Rice to their Indian counterparts, the Indians on September 24 joined the United States and Europeans in voting yes on an IAEA board resolution that found Iran in non-compliance with its non-proliferation obligations but deferred the matter of when and how the Iran question should be referred to the United Nations Security Council. This was a positive step but not yet an indication that India is prepared to use its influence in a sustained and determined way to get Iran to abandon its plans for an enrichment facility capable of producing both fuel for civil nuclear reactors and fissile material for nuclear bombs. Indeed, since the IAEA vote, the Indians have sought to mollify the Iranians, stating that they had acted in Iran's interest by persuading the Europeans to back down from seeking an immediate referral to the Security Council. The key test in the months ahead will be whether India makes a real effort to persuade Iran to forgo an enrichment capability and whether it eventually supports referral to the Security Council, which is required by IAEA statute after a board finding of non-compliance.

The risks of the nuclear deal could also be reduced by preserving some distinction between NPT parties and non-parties in terms of the nuclear exports they would be permitted to receive. A long-standing element of the non-proliferation regime has been the "NPT preference policy"--giving NPT parties benefits in the civil nuclear energy area not available to those outside the NPT. The July 18 joint statement undermines that policy by calling for "full" nuclear cooperation with India. A way of maintaining some preferential treatment for NPT parties would be to modify U.S. law and the NSG guidelines to permit nuclear-related exports to non-parties except equipment, materials or technologies related to sensitive fuel-cycle facilities, including enrichment, reprocessing and heavy-water production. Such a distinction would permit India to acquire natural uranium, enriched fuel, nuclear reactors and a wide range of other nuclear items, but it would retain the ban on transfers of those items that are most closely related to a nuclear weapons program.