With the world nuclear order shattered by the Indian and Pakistani atomic tests, the US and other big powers are scrambling to halt an arms race in South Asia and shore up global nonproliferation regimes.
The US and other countries are discussing holding a series of high-level meetings, starting this week with the five permanent members of the United Nations Security Council.
Both India and Pakistan have indicated a possible willingness to talk about some ideas under consideration, such as renouncing further tests and renegotiating existing arms-control pacts that both refused to sign.
But there are enormous obstacles to cooling the upsurge in one of the 20th century's most intractable rivalries. These include a lack of leverage over India and Pakistan and differences on what steps to take. Russia, France, China, and others oppose punitive sanctions.
"We are trying to turn around the trend, and it is a very difficult thing to do from the outside," says State Department spokesman James Rubin. "Nevertheless, the basic goal ... is to try to see how we can encourage the parties to take steps to reduce the possibility of escalation."
The crisis erupted May 11, when India conducted three underground nuclear blasts, its first since exploding what it called a "peaceful" device in 1974. It held two more tests on May 13.
The UN Security Council's five permanent members may take on India and Pakistan.
The US and Japan responded by imposing economic sanctions.
Pakistan, ignoring pleas for restraint, detonated what it said were five devices on May 28, although some experts question the number because of the low yield detected by seismic monitoring. Despite worldwide outrage and the imposition of US and Japanese sanctions, Pakistan detonated a sixth device on Saturday.
The final Pakistani test gave new urgency to international efforts to find ways of lowering the tensions. The proposed meeting of the permanent UN Security Council members and established nuclear powers - the US, China, France, Britain, and Russia - may be followed by talks between them, Germany, Japan, and Canada in London June 12. India and Pakistan could then be brought into the discussions.
Australia is also calling an emergency meeting of the Geneva-based UN Conference on Disarmament for Tuesday.
The Clinton administration is hoping to win broad support for a series of measures that include urging India and Pakistan to renounce further tests and sign the 1996 Comprehensive Test Ban Treaty (CTBT). It also wants them to join negotiations in Geneva on a worldwide halt to the production of nuclear-weapons-grade material, and to refrain from placing atomic warheads on their missiles.
The administration's most ambitious goal is encouraging the foes to convene talks on improving relations, including resolving their dispute over the divided Himalayan region of Kashmir.
Some experts say one major problem the administration may encounter is resentment shared by India and Pakistan over what they regard as its lack of attention to South Asia, home to the poorest one-sixth of humanity.
In order to win their cooperation, these experts say, the US will have to offer them incentives. These could include providing experts to advise them on safeguards for avoiding inadvertent nuclear conflict such as reviving the use of a hot line that is now virtually dormant, the creation of nuclear doctrines, and other confidence-building steps.
The US might also provide both with intelligence on what the other is doing in order to improve deterrence. Finally, experts say Washington many have to refrain from strictly enforcing economic sanctions that could devastate their already-shaky economies, fueling further instability.
"The least bad way out of this situation would be for India and Pakistan to stop where they are," says Gideon Rose of the New York-based Council on Foreign Relations. "It would be nice if outside powers would help them do that by promising to lift sanctions and throw in some other benefits." In considering incentives, President Clinton will have to decide whether to make a planned trip to Pakistan and India later this year.
PERHAPS the greatest obstacle confronting the US and its partners is the total lack of trust between mostly Hindu India and Muslim Pakistan. Born in the partition of the subcontinent, which saw vast population exchanges that left an estimated 500,000 people dead, the two have fought three wars since independence in 1947.
Their ongoing enmity is manifest across a spectrum of issues. But none is more serious than their unresolved dispute over Kashmir, the cause of two of their wars. India controls two-thirds of the region and the foes exchange daily gunfire across the frontier.
Neither is prepared to renounce its claim to Kashmir, although India would accept a settlement that leaves each side with the territory it now controls. Pakistan, which has been backing a rebellion by Islamic radicals in Indian-held Kashmir, advocates a referendum, knowing that the region's overwhelmingly Muslim population would likely reject joining India.
Another major obstacle is the refusal of the US to mediate in the dispute. Not only is it unwilling to take on the enormous task of untangling the competing claims, but India adamantly rejects outside intervention, pointing to a 1972 pact with Pakistan mandating a bilateral resolution.
"The Indians don't want us there and ... we don't want a role unless they want us," says a US official. There are other hurdles confronting the US and its partners, including their own nuclear weapons policies.
In negotiating the CTBT, the five established nuclear powers spurned demands by India and other states to include provisions requiring them to agree to seek total atomic disarmament. The Pentagon opposes such a stance, saying US security requires maintaining nuclear arms.
India, which has long accused the established nuclear powers of trying to preserve their "exclusive club," refuses to sign the CTBT unless they agree to total disarmament. It would undoubtedly make a similar demand in any renegotiation of the accord. Pakistan says it will only sign the CTBT if India does.