Washington ? American diplomacy centered on a single word has led to a fragile truce between India and Pakistan. By persuading Pakistani President Pervez Musharraf to add the word “permanently” to his promises to stop aiding cross-border terrorism against India, the United States has averted immediate catastrophe and may have opened the way for a strategic realignment in Asia.

Defining precisely what permanently means which is an indirect way of establishing the guarantees India needs to relax its still-threatening mobilization of troops and weapons is a work in progress. But Deputy Secretary of State Richard Armitage has initially coaxed enough specifics out of Musharraf about dismantling terror camps in Kashmir to allow the two adversaries to move back from the brink.

Effective diplomacy, if belated. A clearer and more insistent engagement by Washington in March or April to get Musharraf to stop double-dealing on terrorism might have averted the crisis altogether. And for the truce to hold and lead to greater reductions in tension, the United States must remain deeply engaged in the region.

But there is an existential quality to the new commitments Musharraf has given. If he follows through, the general will abandon more than the grisly tactic of murder by proxy. He will sacrifice a fundamental lie that he and his nation have told themselves about Kashmir since he seized power in October 1999.

The lie was that terrorism in Kashmir would significantly affect the outcome of Pakistan’s multiple disputes with India. Pakistan has no other visible hope of getting its larger, more powerful and prosperous neighbor to end its control over two-thirds of Muslim-majority Kashmir. So Musharraf has pretended that he had an answer one written in the blood of the Indian occupation force and Pakistanis pretended to believe it.

But terrorism against a billion people lacks the force of terrorism against a few million Israelis. Nor does Kashmir resemble Jerusalem as a coveted, cherished goal. What is important to both India and Pakistan is that the other not have Kashmir. Their national identities are bound up in denying possession of it to the enemy. This is a conflict even more artificial therefore more unyielding to reason, and savage than most such struggles.

Without the myth of an effective terror war, Pakistan accepts, at least implicitly, a status quo that will gradually become the final outcome: an international frontier along the present line-of-control in Kashmir.

Armitage did not have to dwell on the immediate risks the Pakistani general faced when they met in Islamabad on June 6. The United States had already told Musharraf it would not be able to stop the Indians from attacking if he offered no movement. Washington would not come to his aid if that happened. And China, pursuing better relations with India, had also let Pakistan know it would not intervene if war came.

Against this bleak horizon Musharraf took up the U.S. suggestion that a pledge to halt permanently the infiltration that has been episodic over the past six months was the only way to move the Indians off war footing. The change was announced that day not in Islamabad or in New Delhi, but in Washington, as if to emphasize the American role in guaranteeing the promise.

The essential new element is Musharraf’s undertaking to close down the 50 to 60 terrorism “camps” the Indians have identified in Kashmir. These range from a collection of a few tents in fields to well-established urban neighborhoods that terrorists control. But Musharraf is now committed to ripping out the plumbing of the terror network created by his intelligence services.

India has offered a few immediate symbolic tension-reducing gestures in response, with more to come in July and then troop reductions in Kashmir if local elections there in October proceed peacefully. All this is contingent on Musharraf keeping his word, and surviving an expected Islamic fundamentalist backlash at home.

There is much to worry about in the short term. But India’s acceptance of America’s role as an honest broker in this crisis is a strategic shift worth developing.

Indian Prime Minister Atal Bihari Vajpayee seemingly overruled his hawks not because he believed Musharraf, but because he believed George W. Bush. There is now an opportunity to use this crisis to reverse decades of mutual mistrust between Washington and New Delhi, which had feared Bush was resuming the U.S. “tilt” toward Pakistan that prevailed during the Cold War. That is the big picture the Bush administration must keep in view.

Jim Hoagland is a columnist for Washington Post Writers Group.