The strain between the United States and what had been its "chief ally in the global war on terror," Pakistan, is growing worse. Because of worsening conditions in Afghanistan and the rising number of U.S. and NATO deaths, the United States launched its first helicopter-borne cross-border raid into Pakistan against insurgents. Officials there claim 15 civilians were killed. There also have been at least seven missile strikes since mid-August.

At least 113 U.S. military personnel have been killed in Afghanistan this year, making it the deadliest in the seven-year operation. Insurgents in Pakistan's western, tribally governed regions bordering Afghanistan are using those territories to launch attacks against U.S. and NATO forces. Also, al-Qaida and Taliban leaders, including Osama bin Laden and his deputy, Ayman al-Zawahri, are believed to be sheltered in these loosely governed regions.

When he was in power, Pakistani President Pervez Musharraf committed his military and intelligence forces to helping neutralize insurgents in his country's western regions, but they never were very effective militarily. Also, the military action proved to be extremely unpopular with the people of Pakistan and contributed to Musharraf being forced from office earlier this year.

With a new government in place, U.S. officials had hoped for increased cooperation with Pakistan. But the war on terror remains highly unpopular there, and anti-American sentiment runs deep.

It was reported last week by The New York Times that President George W. Bush in July authorized looser rules of engagement along the Afghanistan-Pakistan border, which led to the August raid by Navy SEALs and the increased missile attacks. The Pakistani government reportedly was not consulted about this change in U.S. policy. NATO rules still do not allow the cross-border attacks.

Last week, citing its sovereignty, Pakistan's civilian and military leaders condemned the U.S. incursion. Whether those condemnations were meant only to sooth an angry public, we do not know. But introducing U.S. troops into a nation against its will is dangerous. While Pakistan can do little to stop the raids, its cooperation still is needed if the United States and its allies are ever to be successful in Afghanistan. President Bush must do his best to protect allied forces in Afghanistan but, militarily, the United States must tread lightly in Pakistan or risk a split with its major ally in the region.

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