"We say to every mujahid Muslim, if there is an opportunity, do not waste it," said the statement Monday from Al Fajr Media Center, the terror network's online voice. "Do not consult anyone about killing Americans or destroying their economy."

The message praised Bin Laden for his "long-term planning and vision," but proposed exactly the opposite: "We also incite you to carry out acts of individual terrorism with significant results, which only require basic preparation."

The message implicitly acknowledged that the demise of Al Qaeda's founder leaves its core in a weakened position. Even before Bin Laden's death, the rise of affiliates, notably Al Qaeda in the Arabian Peninsula in Yemen, had shifted attention and energy away from the parent organization in Pakistan.

Now, with a handful of flawed or little-known candidates ready to succeed Bin Laden, but no one with his status and charisma, the future of the network's old hub is uncertain. Some American intelligence analysts believe that the fact that more than 10 days have passed without the announcement of a successor could be a sign of a power struggle.

"The core is diminished by Bin Laden's death — it's a big blow," said Daniel L. Byman, a former Central Intelligence Agency and 9/11 Commission staff member, now at Georgetown University.

Intelligence analysts from the C.I.A. and a half-dozen other agencies poring over the computer files and documents seized from Bin Laden's compound in Abbottabad, Pakistan, have been impressed by the degree to which he stayed in touch with underlings in Pakistan and affiliates abroad, said officials briefed on the assessment. The material so far has not yielded leads on plots, said a senior law enforcement official, but it has given greater insight into Bin Laden's role.

He mused in a notebook containing a dozen handwritten pages about new ways to attack the United States, including targeting trains and trying to recruit among American ethnic minorities. On dozens of thumb drives and CDs and 10 hard drives, analysts are finding years of letters of instructions to subordinates and spinoffs, which were then e-mailed by couriers from Internet cafes. It is not always clear that the instructions were received or obeyed.

"Bin Laden was issuing directives in detail to his deputies and to the affiliates — actions to take, thoughts on who should be leaders," said an official familiar with the intelligence. "He was very much trying to exercise control."

Whether a replacement can exercise the same influence is in question.

"Bin Laden was the only person with the stature that when he spoke, the affiliates would listen," said the official, who spoke on the condition of anonymity. "It's unlikely that they will listen to the same degree to any of the others."

Ayman al-Zawahri, the Egyptian doctor who had long been Bin Laden's deputy, is widely viewed as a divisive figure whose ascent to the top position could further weaken the hub of the network. "There's an understanding inside Al Qaeda that Zawahri is not nearly as respected or admired as Bin Laden," said one official.

But under intense pressure both from the C.I.A.'s drones and the stepped-up hunt for Qaeda operatives after the assault on Bin Laden's compound, it will be difficult for any lesser-known leader to establish himself, Mr. Byman said.

"You have to press the flesh," he said. "You have to hold meetings. That's not easy if you're busy trying to stay alive."

Some military and counterterrorism officials believe the competition for leadership of the global jihadist movement is up for grabs, with possible candidates far from Pakistan's tribal area. Among the names mentioned are the leader of Al Qaeda in the Arabian Peninsula, Nasser al-Wuhayshi, a Saudi who served as Bin Laden's personal secretary in the 1990s and who has overseen attacks against both Yemen and the United States.

Mark Mazzetti, Eric Schmitt and Thom Shanker contributed reporting.