NEW DELHI -- A plan by India and Pakistan to implement a treaty barring attacks on each other's nuclear facilities is the latest of many indications that, in the post-Cold War environment, strategic planners in New Delhi and Islamabad see mutual nuclear deterrence as the best way to maintain peace on the volatile subcontinent.

Despite sporadic attempts by the United States and the Soviet Union to prevent the spread of nuclear weapons in a region that has witnessed three wars and innumerable civil conflicts during the last four decades, historical enemies India and Pakistan have continued to move toward a nuclear face-off, with each country using the threat of atomic warfare as a buffer against conventional military attack.

Although implementation of the treaty -- signed in 1988 but never put into effect -- marks a step back from immediate military confrontation, it is seen by Indian and Western analysts as a shield behind which each country can pursue its nuclear program with a semblance of security. In part because of the treaty agreement, any new initiative to reduce Indo-Pakistani tensions might have to concentrate on controlling nuclear weapons, rather than banning them outright, some analysts believe.

"Our efforts should now be concentrated not on nonproliferation, which is no longer feasible, but on steps toward avoiding the risks of nuclear war," said K. Subramaniyam, a prominent Indian defense analyst and an advocate of India's nuclear program.

The attack ban treaty, Subramaniyam said, will help to establish nuclear deterrence between India and Pakistan and is a step toward what he called "the next stage" of Indo-Pakistani relations, which will involve "a balance of {nuclear} deterrence at perhaps low levels."

In that respect, the treaty agreement is only one in a series of events during the last year hastening momentum toward a nuclear standoff on the subcontinent.

An uprising by Moslems in the disputed Indian state of Kashmir has rekindled old conflicts over religion and territory, leading India and Pakistan to send troops and weapons to their border. Concerned that war would erupt, Pakistan accelerated its military nuclear program to the point where U.S. intelligence officials now believe the country is in virtual possession of a crude nuclear bomb.

India, which tested a nuclear explosive in 1974, is believed to be capable of deploying nuclear bombs soon after the start of any armed conflict.

While India and Pakistan have lurched toward confrontation, the collapse of the Cold War reduced the influence that Washington and Moscow are willing or able to wield over their traditional subcontinental allies.

In October, the Bush administration suspended all military and economic aid to Pakistan, citing a U.S. law banning aid to nations developing nuclear weapons. In previous years, U.S. concern about Pakistan's nuclear program was subordinated to Cold War goals such as protecting Pakistan from Soviet expansionism and ousting Soviet troops from Afghanistan. This year, with the Afghan war winding down and U.S.-Soviet confrontation on the wane, the U.S. Congress showed it was willing to jettison the Pakistan alliance if Islamabad declines to give up its pursuit of a nuclear bomb.

Because $560 million in annual aid is virtually the only leverage the United States has over Pakistan, this autumn's aid cutoff has reduced Washington's ability to influence Islamabad's nuclear and military policies. At the same time, the aid cutoff has fueled anti-American feeling in Pakistan.

The U.S. break with Pakistan has been paralleled by a less dramatic diminution of Moscow's longstanding alliance with India. Beset by domestic crises and desperate for hard currency, Moscow has made it clear that India must expect a reduction of direct Soviet military and economic assistance in the years ahead.

The vacuum left by the superpowers has been filled by resurgent religious nationalism in India and Pakistan, where national interest is described increasingly in terms of ancient territorial and Hindu-Moslem feuds, rather than the post-World War II conflict between East and West.

In the military arena, this trend has bolstered the positions of Indian Hindu activists and Pakistani Islamic radicals, who argue that nuclear weapons are essential to ward off an unyielding foe.

Superpower lobbying did appear to help cool Indian and Pakistani tempers at the height of the tensions over Kashmir last spring, but since then Washington and Moscow have been shunted to the sidelines, distracted by the Persian Gulf crisis and unable to follow through on a privately discussed regional initiative to ban nuclear weapons on the subcontinent.

Some diplomats believe such a superpower-sponsored initiative could be taken up again once the gulf crisis is resolved. In the meantime, however, India and Pakistan appear to be moving independently to establish their own system of nuclear deterrence that may be difficult for anyone to negotiate away.