Toward the end of his decade in hiding, Osama bin Laden was spending as much time exchanging messages about al-Qaeda’s struggles as he was plotting ways for the terrorist network to reassert its strength.

Over the past year, the al-Qaeda leader fielded e-mails from followers lamenting the toll being taken by CIA drone “explosions” as well as the network’s financial plight, according to U.S. officials who have completed an exhaustive review of the trove of bin Laden files collected at his compound after the May 2 U.S. raid that killed him.

Bin Laden approved the creation of a counterintelligence unit to root out traitors and spies, only to receive a complaint in mid-2010 from the unit’s leader that it was losing the “espionage war” and couldn’t function on its paltry budget.

Just months before the Arab Spring took hold, bin Laden warned affiliates in Yemen and elsewhere that it was too soon to create an Islamic state. The Saudi native, whose family had made its fortune in construction, concluded that there wasn’t “enough steel” in al-Qaeda’s regional support structures to warrant even tentative steps toward reestablishing the caliphate.

Such sober assessments and references to setbacks are among the fine-grained details that U.S. intelligence analysts have gleaned to assemble a new and more nuanced portrait of al-Qaeda and its founder in the aftermath of the raid on bin Laden’s compound in the Pakistani city of Abbottabad.

Analysts at the CIA and other agencies are likely to continue poring over the bin Laden files for years. But the multi-agency task force that was set up to review what officials have described as the largest cache of terrorism records recovered to date finished its job and was disbanded last month.

“We believe the materials will continue to yield new insights on al-Qaeda for years to come,” said a U.S. counterterrorism official familiar with the task force’s work. “But the task force is done.”

The group produced more than 400 intelligence reports in a span of six weeks and prompted public warnings of al-Qaeda plots against trains and other targets. U.S. officials said the findings also triggered a small number of operations overseas, including arrests of suspects who are named or described in e-mails that bin Laden received.

But officials said that the main value of the data is in enabling analysts to construct a more comprehensive portrait of al-Qaeda and that many of the most recent files found on bin Laden’s computers depict an organization beset by mounting problems even as its leader remained singularly focused on delivering a follow-up to the Sept. 11, 2001, strikes.

“The trove makes it clear that bin Laden’s primary goal — you can call it an obsession — was to attack the U.S. homeland,” said a senior U.S. counterterrorism official. “He pushed for this every way he could.”

The official was one of several who agreed to discuss the conclusions of the bin Laden task force — and provide new details on specific messages sent and received by the al-Qaeda leader — on the condition of anonymity, citing the sensitivity of the subject.

One of bin Laden’s principal correspondents was Atiyah abd al-Rahman, who served as No. 3 in al-Qaeda before bin Laden’s death. A 2010 message from Rahman expressed frustration with the CIA drone campaign, a source of particular concern because many of his predecessors in the third-ranking slot had been killed in strikes by the unmanned aircraft.

“He was saying in the letter that their guys were getting killed faster than they could be replaced,” the U.S. counterterrorism official said.

Other messages sounded a similar theme. At least two came from the head of al-Qaeda’s security unit, a group that had been established to protect against penetrations by informants who might provide targeting tips to the CIA. The group is thought to be behind executions of dozens of suspected informants. In some cases, corpses were found with notes attached declaring that the deceased was an American spy.

The unit leader complains “about having a very low budget, a few thousand dollars,” the official said. The letter refers to “ideas” about how to better guard against informants and electronic eavesdropping. But the most obvious solutions, including restricting meetings and movements, would also hamper al-Qaeda’s ability to function.

Other messages make frequent mention of the organization’s financial hardships, including e-mails in which bin Laden himself complains about the lack of funds. One bin Laden message sent in spring 2010 “instructed a deputy to form a group that would get money through kidnapping and ransom of diplomats,” the U.S. official said.

The message was sent to Rahman.

“The term ‘financial hardship’ was used” in the message, the U.S. official said. But there are no files that provide specific figures or a comprehensive picture of al-Qaeda’s financial position. “There’s not a bank sheet for al-Qaeda,” the official said. “There is some insight into time periods when money was coming in and when it wasn’t and what they were trying to do to get more.”

Kidnappings had been embraced by other militant groups, including the Afghan Taliban, which abducted the Pakistani ambassador to Afghanistan as well as a New York Times reporter in 2008.

Several messages contain mentions of militants seen as suitable candidates for al-Qaeda operations, information that has led to an undisclosed number of arrests by other governments overseas, the officials said.

The exchanges read like status updates between a headquarters and a satellite branch, officials said, with bin Laden pressing far-flung followers for more information on their plans, then waiting, sometimes for weeks, for replies.

The cache contains correspondence between bin Laden and Ayman al-Zawahiri, who recently succeeded bin Laden as al-Qaeda’s leader. The two express frustration that the conflict between al-Qaeda and the United States is not more widely perceived among Muslims as the front of a religious war. They also voice concern about how insurgent killings of civilians in Iraq and elsewhere could undermine al-Qaeda’s standing among Muslims.

U.S. officials said nothing in the messages indicates that either knew where the other was hiding.

Bin Laden repeatedly prods al-Qaeda’s affiliates to put off their regional ambitions to remain focused on attacking the United States. A 2010 message sent to Nasir al-Wuhayshi, the leader of al-Qaeda in the Arabian Peninsula, said that Yemen “was ripe for establishing an Islamic state but that it wasn’t the right time,” a U.S. official said.

AQAP, as the Yemen-based group is known, had already launched high-profile but unsuccessful attacks against U.S. targets, including the attempted bombing of a Detroit-bound airliner on Christmas Day 2009.

The group expressed interest in moving faster to establish local institutions that would enforce sharia law. But bin Laden cautioned against such efforts, saying they didn’t have adequate support, and said the group needed to stay focused on attacking the United States.

Bin Laden’s messages were mostly composed on computers, then smuggled out on small disks or thumb drives by couriers, who would then copy the contents into e-mails that could be sent securely to followers — whether they were mere miles from bin Laden’s compound or overseas.

The analytic task force was based at a CIA facility in Northern Virginia. Officials declined to disclose the current location of the more than 15 computers and 100 storage devices recovered from the bin Laden compound, except to say that they are in FBI custody.

Staff researcher Julie Tate contributed to this report.