In its eagerness to reverse the mounting insurgency in Afghanistan, the United States has embarked on a policy course that could shatter our vital strategic partnership with Pakistan. By allowing American combat forces to freely conduct raids into Pakistani territory, a move that President Bush authorized in July, the United States intends to pressure Pakistani leaders to step up the fight against militants ensconced in the borderlands. But this policy threatens cooperation between the two countries, possibly to the breaking point.

Pakistani insurgents, initially staggered by the U.S. reaction to the Sept. 11 attacks, have rebuilt their organizations in the border regions; from those havens, they launch attacks against U.S. and allied forces in Afghanistan. The 80,000 to 120,000 Pakistani troops that have engaged the insurgents since 2003 have been funded by the United States at a cost of $1 billion a year. Yet whether it is because troops are ill-equipped, poorly trained or unmotivated, operations have been inconsistent and incomplete.

As the Afghan Taliban and al-Qaida have regrouped, Washington has come to question the sincerity of Pakistan's effort. U.S. officials, concerned that elements in Pakistan's security forces are sympathetic to the insurgents and more interested in protecting than pursuing them, understandably want to deal with the threat if Pakistan will not or cannot.

But there is too much at stake for the United States to risk dangerous, misguided policies. Neither intrusions by U.S. Special Forces nor missile attacks by drones will, by themselves, take out the thousands of insurgents and their allies along the frontier. They also cannot seriously disrupt the global terrorist network. No one proposes deploying the tens of thousands of U.S. troops that it would take to saturate the tribal region and sustain any successes. And fighting a united tribal nation on its turf would cause massive civilian casualties. Even a more covert U.S. approach, designed to play radicalized tribal groups against one another, would likely reveal that their hatred for America exceeds any historic or personal animosities.

So what is left? There are no quick fixes. The cooperation of the Pakistani military and its intelligence services, working with a civilian government, remains indispensable. At the moment, however, the Pakistani people offer no support; polls reveal that fewer than 20 percent of Pakistanis view the U.S. favorably. The U.S. invasion of Iraq galvanized their belief that, as in Afghanistan, the war was essentially about defeating Muslims. The U.S. alienated even our Pakistani friends by pursuing policies that came to be perceived as trying to salvage the presidency of Pervez Musharraf and thwart democratic processes.

While there is some comfort to be found in President Asif Ali Zardari's views on combating terrorism, having Zadari as Musharraf's replacement in the role of U.S. point man will not help to build a popular consensus against extremism. Just last week, the parliament voted unanimously to condemn the latest U.S. missile attack on Pakistani territory. If Zardari tries to blunt criticism of the United States, his governing coalition could be threatened. And the likely victor as prime minister in a new election, Nawaz Sharif, has a strongly jaundiced view of U.S. involvement in the frontier and Afghanistan.

Proposals geared toward helping the United States regain the trust of Pakistanis are under consideration. Most, like the Biden-Lugar bill, recognize the importance of nonmilitary assistance that addresses Pakistan's endemic social problems and infrastructure deficits. Measures that help Pakistan weather its economic crisis will have an effect, as will a more favorable trade policy, especially on textiles. The United States can also be more convincing in its commitment to civilian rule and democracy.

By contrast, openly violating Pakistan's territory will make matters worse. And Pakistan can easily retaliate. Most supplies for U.S. and coalition forces in Afghanistan are delivered to the port of Karachi and then shipped by road to Afghanistan. Early last month, trucks seeking to cross the border were stopped, a warning of what might happen if U.S. raids continue. Pakistan's most senior military officer, Gen. Ashfaq Kayani, has said the army will defend Pakistani sovereignty at all costs. Cross-border raids risk provoking direct confrontation between U.S. and Pakistani forces and could accelerate the growing dissension in military ranks over continued Pakistani alignment with the United States.

Terrorist sanctuaries are unacceptable. But eliminating them requires Pakistan's cooperation. The bombing of the Marriott in Islamabad last month was a reminder that we are fighting different faces of the same war. Continuing to carry out uninvited, inconclusive U.S. cross-border attacks will make finding cooperation with Pakistan more elusive.

Weinbaum is a scholar in residence at the Middle East Institute and a former State Department intelligence and research analyst on Pakistan and Afghanistan. He wrote this for The Washington Post.