Senior Bush administration officials have warned in recent weeks that Al Qaeda (search) is regrouping for another massive attack, its agents bent on acquiring nuclear, chemical or biological weapons in a nightmare scenario that could dwarf the horror of Sept. 11, 2001.

But in Pakistan (search) and Afghanistan — where Usama bin Laden (search) and his chief deputy are believed to be hiding — intelligence agents, politicians and a top U.S. general paint a different picture.

They say a relentless military crackdown, the arrests last summer of several men allegedly involved in plans to launch attacks on U.S. financial institutions, and the killing in September of a top Pakistani Al Qaeda suspect wanted in a number of attacks — including the 2002 killing of Wall Street Journal reporter Daniel Pearl and two failed assassination attempts against President Gen. Pervez Musharraf — have effectively decapitated Al Qaeda.

Because of the secretive and underground nature of cells that operate throughout the world, it cannot be known for certain what effect the damage done to Al Qaeda in its home territory has had on operations elsewhere.

Pakistani intelligence agents told The Associated Press that it has been months since they picked up any "chatter" from suspected Al Qaeda men, and longer still since they received any specific intelligence on the whereabouts of bin Laden or any plans to launch a specific attack.

They say the trail of the world's most wanted man — long-since gone cold — has turned icier than the frigid winter snows that blanket the mountains between Pakistan and Afghanistan, where the terror mastermind is considered most likely to be hiding.

Pakistani officials have been quick to hail the long silence as a signal that it has already dismantled bin Laden's network, at least in this part of the world.

"We have broken the back of Al Qaeda," Interior Minister Aftab Khan Sherpao said last month in a speech in Peshawar, the capital of the frontier province on the border with Afghanistan. Musharraf added last week that his government had "eliminated the terrorist centers" in the Waziristan tribal region and elsewhere.

"We have broken their communication system. We have destroyed their sanctuaries," the president told reporters. "They are not in a position to move in vehicles. They are unable to contact their people. They are on the run."

A senior official in Pakistan's Inter-Services Intelligence spy agency told AP he couldn't remember the last time the agency got a strong lead on top-level Al Qaeda fighters.

"Last year, we frequently heard Arabs on radios talking about their hatred for (Afghan President Hamid) Karzai and Musharraf for supporting Americans, and we were able to trace Al Qaeda hideouts in South Waziristan," said the official, who spoke on condition of anonymity. "Lately, such conversations have decreased."

Pakistan's optimism seems to be backed by senior U.S. military officials in the region.

Maj. Gen. Eric Olson, the No. 2 American commander in Afghanistan, said he had seen nothing to indicate that Al Qaeda was attempting to get its hands on nuclear or biological weapons.

There is "no evidence that they're trying to acquire a terrorist weapon of that type and, frankly, I don't believe that they are regrouping," he told AP in a Feb. 25 interview.

"I think the pressure on them here, the pressure on them in Pakistan, the pressure on them in Iraq, is pretty great and it makes very difficult for them to operate," Olson added.

The skeptical assessments from officials here fly in the face of warnings out of Washington, where President Bush is pushing Congress to approve a $419 billion defense budget for 2006.

The Homeland Security Department late last month issued a classified bulletin to officials that bin Laden was enlisting his top operative in Iraq, Abu Musab al-Zarqawi, to plan potential attacks on the United States.

There have also long been fears — though no evidence to date — that rogue Pakistani nuclear scientists might have provided bin Laden's men with the know-how to build a crude atomic device or dirty bomb.

Newly installed CIA director Porter Goss and other senior American intelligence and military officials warned last month that terrorists are preparing for new strikes.

"It may be only a matter of time before Al Qaeda or other groups attempt to use chemical, biological, radiological or nuclear weapons," Goss said at the Senate Intelligence Committee's annual hearing on threats, urging approval of the defense budget.

But Sherpao scoffed at such warnings.

"That is simply out of the question," he said of Al Qaeda's ability to acquire weapons of mass destruction, adding that any Al Qaeda leader who has escaped arrest was "more worried about their own safety."

"How can such people launch attacks with nuclear or chemical weapons?" he asked.

Maj. Gen. Olson, who leaves Afghanistan next month to return to the 25th Infantry Division back in Hawaii, said Al Qaeda leaders were unable to use modern communications for fear of detection and were reduced to "16th century" techniques such as couriers. He said he wasn't discouraged by the success bin Laden and his deputy have had in releasing audio and videotapes filled with threats during the past few months.

"They can deliver all the videotapes they want, as long as they're not delivering weapons that can kill large numbers of people and I am convinced that their ability to coordinate large attacks like that is severely disrupted right now because of the pressure we have on them," he said.