Since June 2012, Peter Bergen, the swashbuckling reporter who serves as CNN’s national-security analyst and a director of the liberal New America Foundation, has been among those in the foreign-policy establishment confidently declaring that “al-Qaeda is defeated.”

The terrorist organization responsible for the September 11, 2001, attacks, he has been arguing, developed “myriad weaknesses that make the group’s offensive capabilities rather puny.” Al-Qaeda’s leader, Ayman al-Zawahiri, proved to be “a black hole of charisma” who inherited from Osama bin Laden “the Blockbuster Video of global jihad and has done nothing to resuscitate it.” Al-Qaeda, Bergen added for good measure, is “more or less out of business.”

As recently as last August, in a debate with me on Wolf Blitzer’s CNN program, Bergen defended this thesis, noting that in 2006 al-Qaeda controlled two-thirds of Iraq and that “now it controls nothing” there.

Last week, however, we learned that al-Qaeda now controls “more territory in the Arab world than it has done at any time in its history.” As for the charisma-challenged Zawahiri, he “is closer to his goal than he has ever been.”

Who wrote that solid report so thoroughly demolishing the Bergen narrative on al-Qaeda’s demise? Why, Peter Bergen did! And good for him — though my praise would be more effusive had he acknowledged to his readers and viewers that (how can I say this gently?) his thinking has evolved.

Bergen is hardly the only high-visibility expert not owning up to what might be considered fairly egregious analytical errors in regard to al-Qaeda. On December 28, The New York Times published the results of its investigation into the September 11, 2012, attacks in Benghazi. Its conclusion: Al-Qaeda was not involved. Only “local” Libyan actors were responsible — not global terrorists. “The investigation by the Times,” reporter David Kirkpatrick pronounced, finds that “Benghazi was not infiltrated by al-Qaeda but nonetheless contained grave local threats to American interests.” Many in the media treated this as the last word on the issue.

Thomas Joscelyn, my colleague at the Foundation for Defense of Democracies — who, not just incidentally, has for the past few years conducted the most persuasive research refuting the “al-Qaeda is dead” spin — immediately noticed that that the Times report “specifically ruled out any meaningful involvement of an ex-Guantánamo detainee named Sufian ben Qumu — a terrorist with longstanding ties to al-Qaeda and the leader of Ansar al Sharia in Darnah, Libya.”

That’s significant because, last Friday, the U.S. State Department formally named ben Qumu a “apecially designated global terrorist” and “the leader of Ansar al-Shari’a in Darnah” — which on Friday was designated as a foreign terrorist organization (FTO) along with Ansar al-Sharia in Benghazi.

According to State, both these groups were indeed “involved” in the September 11, 2012, attacks on the U.S. mission and annex in Benghazi. Surely, the notion that the leader of one of them had no idea what his fighters were up to strains credulity. What’s more, back in November, and based on confidential conversations with U.S. intelligence officials, Joscelyn and The Weekly Standard’s Stephen Hayes reported that ben Qumu trained some of the jihadists who carried out the attacks in Benghazi.

As Joscelyn also has reported, ben Qumu was one of the “Afghan Arabs” who “fought alongside al-Qaeda and the Taliban in Afghanistan, and maintained ties to several other well-known al-Qaeda leaders.” An alias he used was found on the laptop of an al-Qaeda operative responsible for overseeing the finances for the September 11, 2001, terrorist attacks. Information on that laptop also indicated that ben Qumu was an al-Qaeda “member receiving family support.”

That’s not all the Times missed: An August 2012 report published by the Library of Congress in conjunction with the Defense Department, titled “Al-Qaeda in Libya: A Profile,” reveals that ben Qumu and his Ansar al-Sharia fighters were “believed to be close to the al-Qaeda clandestine network” in Libya — a network “headed by al-Qaeda operatives who report to al-Qaeda’s senior leadership in Pakistan, including Ayman al Zawahiri.”

This and other evidence can lead only to one conclusion: Terrorists and terrorist organizations operationally tied to al-Qaeda and sharing al-Qaeda’s global Islamist revolutionary ideology were involved in the murder of U.S. ambassador J. Christopher Stevens and three other Americans on September 11, 2012.

As if to confirm that, on Wednesday the Senate Intelligence Committee released a bipartisan report on Benghazi clearly stating that as early as June 12, 2012, the Defense Intelligence Agency (DIA) was reporting “growing ties” between al-Qaeda “regional nodes” and “Libya-based terrorists.” A month later the CIA reported that al-Qaeda-affiliated groups in Libya were enhancing their “capabilities” and expanding their “operational reach.”

As I write this, the Times has not revised its conclusions at all. On the contrary, a story last week continued to press the narrative that ben Qumu was only “a former driver for a company controlled by Osama bin Laden” and that, while he has been “identified as a leader of Ansar al Shari’a in Derna [an alternate spelling of Darnah], . . . officials briefed on the designations and the intelligence reports said that there was no evidence linking him to the attack” in Benghazi.

There has been confusion as well regarding the Ansar al-Sharia organization in Tunisia, which was responsible for an assault on the U.S. embassy in Tunis on September 14, 2012. Most in the media dismissed that attack, too, as merely “local” and not al-Qaeda-related. But Joscelyn has connected the dots between al-Qaeda and the Tunisian branch of Ansar al-Sharia which also was designated by the State Department on Friday. The designation specified that Ansar al-Sharia Tunisia “is ideologically aligned with al-Qaeda and tied to its affiliates, including AQIM” (al-Qaeda in the Islamic Maghreb).

The various Ansar al-Sharia groups, in both Libya and Tunisia, Joscelyn reports, have been involved in “sending recruits off to Jabhat al Nusrah — an al-Qaeda group fighting in Syria.” If that’s not evidence of an al-Qaeda link, pray tell, what would be?

I want to be fair: These are complicated issues. Reporters, even good ones, sometimes don’t gather all the pieces of the puzzle, or they get spun by sources with an agenda. Analysts, however diligent, sometimes produce flawed analyses. Still, we should be troubled when we see a pattern of data misinterpretation regarding al-Qaeda (and Iran, too — but we’ll leave that for another day) with no one learning from their mistakes.

And this has been going on for years. One example: Back in July 2007, seven months after the start of the “surge” in Iraq, but several months before that battle plan’s success had become indisputable, Fawaz Gerges, then a professor at Sarah Lawrence College (now a professor at the London School of Economics), told PBS’s Bill Moyers that “the American military presence in Iraq . . . has become a liability against America’s vested interes.t . . . The longer we stay in Iraq, the more we help al-Qaeda spread its ideology and tactics.”

A few years later, President Obama embraced that analysis and removed America’s military presence from Iraq, leaving behind not even a residual force to help prevent al-Qaeda from regrouping and reestablishing a foothold in the heart of the Arab Middle East. How has that policy worked out? See the report by Peter Bergen cited above.

— Clifford D. May is president of the Foundation for Defense of Democracies, a policy institute focusing on national security.