Indian Foreign Secretary Shivshankar Menon was in Washington last week to save the troubled U.S.-India nuclear deal by which the U.S. would end longstanding restrictions on nuclear cooperation with India. Nonproliferation watchdogs and many countries that do not have nuclear weapons howled over this radical jettisoning of rules established to reward states that signed the Nuclear Nonproliferation Treaty.

Months after Congress blessed the concept, negotiations have stalled on at least two major sticking points: India desires advance consent to extract plutonium from reactor fuel that would be provided by the U.S. and other foreign suppliers and opposes any cutoff in cooperation should it test a nuclear device again.

These are not merely technical details. The Republican-controlled Congress of last year insisted that the plutonium reprocessing and nuclear testing conditions were necessary to maintain the integrity of U.S. and international nonproliferation policies. It would be irresponsible for a Democratic-controlled Congress now to allow these provisions to be negotiated away.

Providing long-term consent to reprocess spent fuel from reactors would undermine the current U.S. policy of not encouraging the use of plutonium and highly enriched uranium in the civilian nuclear fuel cycle, particularly in breeder reactors (which can make more plutonium than they burn up). Allowing India to test again without risking foreign nuclear cooperation would severely undermine global nonproliferation.

While Congress gave President Bush the benefit of the doubt on nuclear cooperation with India, it did not give him a blank check. Congress retained the right to stop the agreement from entering into force if it did not uphold the conditions it established last year in authorizing the administration to finalize the agreement with India.

The agreement is nowhere near completion. If the Indian press is a reliable guide, Indian officials believe the Bush administration has tightened the terms of the vague general agreement reached by President Bush and Prime Minister Manmohan Singh in July 2005. The two leaders agreed generally that India would gain full international cooperation in return for accepting the nonproliferation obligations that the U.S. and other established nuclear-weapon states follow. India insists full cooperation should mean that the United States not only let India reprocess U.S.-origin spent fuel, but provide approval 30 years in advance.

Providing a 30-year-long consent for reprocessing would put India on par with Japan and our European allies as well as signal support for reprocessing spent fuel and using plutonium in breeder reactors. For thirty years, U.S. policy has been not to encourage the use of plutonium or highly enriched uranium in the civilian fuel cycle. Since the September 11, 2001 attacks, that imperative surely has grown.

More troubling, however, is India's insistence that the cooperation agreement contain no negative consequences should India test a nuclear device in the future. Under U.S. law, a nuclear test by a state such as India would trigger two actions: nuclear exports would end (unless the President asks for and Congress grants a waiver) and the U.S. could ask for its material and equipment back. Congress, in the Hyde Act, waived the required cutoff of exports for India's 1998 nuclear test, but not for future tests. As for the right of return, India apparently is most worried about fuel stockpiles and reserves that the United States might supply, which it could then ask for back.

In the last two years of negotiations, however, the United States has given inches and India has taken miles. From the July 2005 announcement of the initiative to President Bush's visit to India in March 2006, the United States has repeatedly missed opportunities to prevent this cooperation from eroding the global nonproliferation bulwark.

An Indian agreement to stop production of fissile material for nuclear weapons would have strengthened the nonproliferation regime and U.S. leadership, but U.S. officials didn't press hard for that. An Indian agreement to place all of its electricity-producing reactors under international inspections would have made the Indian plan to separate its military from its civilian nuclear programs meaningful, but the U.S. retreated from that. The next phase of Indian nuclear development ? the construction of fast breeder reactors ? could take place entirely outside of international safeguards.

While it is too late to correct these missteps, U.S. law still provides for some barriers to proliferation, and U.S. negotiators should ensure that the peaceful nuclear cooperation agreement meets the letter and spirit of that law. The agreement should specify case-by-case approval of Indian reprocessing of U.S. spent fuel, and explicitly require termination of cooperation and return of U.S. materials and equipment should India test. Surely, no nonproliferation benefits are served by further Indian nuclear tests and the U.S. nuclear cooperation agreement needs to reflect that. Anything less should be rejected by Congress.

Sharon Squassoni is a senior associate in the Nonproliferation program at the Carnegie Endowment for International Peace.