As if it were not enough that the U.S. is seemingly mired in Iraq and Afghanistan, and may be confronted with an Iran armed with nuclear weapons, now Pakistan has emerged as the latest site of quicksand in Southwest Asia.

"We are really worried about Pakistan," said a U.S. official with access to top-level thinking. "It is the latest fault line in that part of the world." Until now, the Bush administration had relied on Pakistan, a largely Muslim nation, to be an ally in the war on terror that could persuade other Muslim nations of the good intentions of the U.S.

What's particularly worrisome is the possibility that Pakistan's nuclear weapons could fall into the hands of resurgent Islamic extremists. Robert Wirsing, a scholar specializing in South Asia at the Asia Pacific Center for Security Studies here, says: "Our foremost concern would be having nuclear weapons get into the wrong hands."

Senior officers of the Pakistani army have asserted that they have their nuclear weapons under close control. The U.S., while displeased with Pakistan's nuclear program, is reported to have assisted Pakistan in establishing safeguards over its nuclear weapons, including keeping them disassembled and components separated.

Pakistan's first nuclear test was fired in 1974, shortly after a test by archrival India. In 1998, Pakistan said it conducted six nuclear tests. The Natural Resources Defense Council in Washington estimates Pakistan has built 24 to 48 warheads. The Carnegie Endowment for Peace in New York says Pakistan has produced enough enriched uranium for 30 to 55 weapons.

Today, Pakistan is causing anxiety because it appears to be paralyzed politically. President Pervez Musharraf's support has plummeted, leaving him poised between resigning, declaring an emergency to stay in power or running in an uncertain election. He remains a general despite demands that he doff his uniform before the election in October; he says he will take it off only after he has been re-elected.

Says a Pakistani scholar reached by e-mail: "The president is so insecure that he fears once he takes off his army uniform, he will not enjoy the same authority as he does with it on."

Musharraf has evidently been so weakened that he had a political opponent, former Prime Minister Nawaz Sharif, unceremoniously hustled out of the country to Saudi Arabia only four hours after he returned from exile earlier this month. Another opponent, former Prime Minister Benazir Bhutto, says she will return from exile in London in October.

More evidence of the consequences of paralysis appeared in a U.S. National Intelligence Estimate in Washington saying Pakistan has become a safe haven for al-Qaida terrorists. Repeated reports say their leader, Osama bin Laden, is hiding in the remote reaches of northwestern Pakistan, which borders on Afghanistan.

The Taliban, the Islamic extremists who ruled Afghanistan from 1996 until they were destroyed by the U.S. and Afghan allies in 2001, are resurgent in Pakistan. Many of its leaders were killed, were taken prisoner, or fled in 2001. But one leader, Mullah Omar, eluded capture and has recruited new followers whom some analysts call the "Neo-Taliban."

The Pakistani scholar reinforced that view, saying: "There is great resentment against the current regime, their policies and alignment with the West in the fight against terror. The North West Frontier Province has seen the spread of the Taliban of late. The Taliban is giving people there an alternative leadership."

Part of Musharraf's deteriorating posture — a recent poll had his approval rating at 34 percent, down by 20 points — could be attributed to his support of the U.S. The Pew Research Center found seven in 10 Pakistanis worried that the U.S. would attack their country; 64 percent said the U.S. was more of a threat than India, with whom Pakistan has fought three wars and continues to detest.

What Pakistanis perceive to be long-standing contradictions in American policy has not helped. A former Pakistani ambassador to the U.S., Maleeha Lodhi, wrote nearly 10 years ago that Pakistan had stood with the U.S. during the Cold War and the Soviet invasion of Afghanistan in 1979.

But, she said: "The end of the Cold War persuaded the U.S. to re-evaluate and downgrade its relationship with Pakistan on the ground that the new global environment did not warrant the old strategic partnership."

An American former official informed on U.S.-Pakistan relations seemed to agree: "They don't trust us. And I guess we shouldn't trust them. It's not much to fall back on when things go wrong."

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.