U.S. intelligence agencies badly misjudged al-Qaida's ability to take advantage of political turmoil in the Middle East and regain strength across the region after Osama bin Laden was killed, according to a new book by the CIA's former deputy director.

Senior U.S. intelligence officials have previously acknowledged failures to anticipate the Arab Spring movement, which toppled governments in the Middle East and North Africa. But the former official, Michael Morell, wrote that the CIA compounded those errors with optimistic assessments that the upheaval would prove devastating to al-Qaida.

"We thought and told policy-makers that this outburst of popular revolt would damage al-Qaida by undermining the group's narrative," Morell wrote in the book, a copy of which was obtained by The Washington Post ahead of its release later this month.

Instead, "the Arab Spring was a boon to Islamic extremists across both the Middle East and North Africa," he said. "From a counterterrorism perspective, the Arab Spring had turned to winter."

The acknowledgment represents one of the most bleak assessments of the CIA's performance during that tumultuous period by an official who was in the agency's leadership at the time.

Four years after the initial street protests in Tunisia that set off the Arab Spring, al-Qaida and its progeny have gained territory and strength in countries such as Egypt, Libya, Syria, Iraq and Yemen. U.S. officials have said recently that they expect conflicts exploited by extremists to persist for a decade or more.

The CIA declined to comment on the criticism in Morell's book, but U.S. officials stressed that events turned rapidly to al-Qaida's advantage largely because the political movements that seemed promising at first have largely failed to lead to effective new governments.

Morell's book traces his three-decade career at the agency but is largely focused on the CIA's counterterrorism missions — and the often-ensuing political fallout — since the Sept. 11, 2001, attacks. It is titled "The Great War of Our Time."

Morell defends the CIA's use of brutal interrogation measures on terrorism suspects and is sharply critical of a multi-year investigation by the Senate Intelligence Committee that found no evidence that the agency obtained any significant intelligence from detainees subjected to waterboarding and other methods.

He reiterates his defense of the Obama administration's response to the 2012 attacks on U.S. diplomatic and intelligence compounds in Benghazi, Libya, but questions decisions by the State Department security team before U.S. Ambassador J. Christopher Stevens was killed. Morell said that the CIA regarded the rising violence as so severe that he had traveled to Tripoli a year earlier to urge the Libyan government to mobilize against Islamist groups.

The book touches on subjects such as leaks by former intelligence contractor Edward Snowden and the 2011 raid on bin Laden's compound in Abbottabad, Pakistan. It includes an apology to former Secretary of State Colin L. Powell for the CIA's erroneous prewar assessments of Iraq's weapons programs but accuses then-Vice President Dick Cheney of pressuring agency analysts to find links between Iraq and al-Qaida that did not exist.

The book's most sobering passages are devoted to al-Qaida's resurgence after bin Laden's death, which had raised hopes among U.S. counterterrorism officials that the organization was on a path to defeat.

Although the militant group Islamic State severed ties with al-Qaida and is widely seen as being mainly focused on its regional ambitions in Iraq and Syria, Morell said that the group is ideologically indistinct from al-Qaida. The Islamic State "has announced their intentions to attack us — just like bin Laden did," Morell wrote.

U.S. intelligence agencies failed to anticipate the Arab Spring in part because the CIA and other U.S. spy services had over time become deeply dependent on their counterparts in Middle Eastern governments for insights.

"We were lax in creating our own windows into what was happening, and the leadership we were relying on was isolated and unaware of the tidal wave that was about to hit," Morell wrote. As those governments fell, so did their ability to contain militant groups inspired by al-Qaida.

The book's section on the Arab Spring provides new details on failed U.S. efforts to influence the outcome in Egypt and other countries through secret back-channel talks.

Morell said that he became a conduit for communications between the Obama administration and Egyptian President Hosni Mubarak's intelligence chief.

The discussions were set in motion after Morell was contacted by a former CIA director who indicated that the Egyptian spy chief, Omar Suleiman, was looking for direction from the United States.

Reached by phone, Morell declined to identify which former agency director had contacted him or the American businessman who began relaying messages to Suleiman.

The CIA came to believe that Suleiman was searching for U.S. guidance on how he might survive the uprising, and perhaps even maneuver to succeed Mubarak, by using a communications channel he could keep secret from the Egyptian leader.

Morell said he used the arrangement to deliver messages, including one urging Suleiman to persuade Mubarak to deliver a speech saying that he would step down and appoint a transitional council — part of a last-ditch effort to achieve a peaceful transfer of power.

The message was composed by then-White House adviser Denis McDonough, according to Morell, and approved by other senior officials on President Barack Obama's national security team. "Later my contact phoned me back and told me that Suleiman had not only gotten the message but that he had convinced Mubarak to make those points in his remarks," Morell said.

But as White House officials watched Mubarak's address on Feb. 1, 2011, "it quickly became clear that Mubarak was heading in a different direction from the Suleiman talking points."

Mubarak instead tried to cling to power. Ten days later, he was forced to resign anyway, a move that Suleiman announced amid pressure from the country's military leadership. Suleiman was also forced to step down and died in 2012.