Terrorism analyst Paul Cruickshank, editor-in-chief of West Point's CTC Sentinel, who reviewed al Qaeda's answers, says it is possible "they feel buoyed by the Biden administration's decision to pull out troops from Afghanistan, but they may also be seeking to deflect attention from the many recent losses."

America's longest war will end

Today, the terror group that once roared to world attention is reduced to a whimper, but it is far from dead. And now says it's planning a comeback after US forces leave Afghanistan, by partnering once again with the Taliban.

In its response to CNN, two members of al Qaeda's subcontinent broadcast branch heap praise on the Taliban for keeping the fight against America alive. "Thanks to Afghans for the protection of comrades-in-arms, many such jihadi fronts have been successfully operating in different parts of the Islamic world for a long time," the spokesperson says.

US Secretary of State Antony Blinken agreed, telling ABC's "This Week" earlier this month: "We went to Afghanistan 20 years ago, and we went because we were attacked on 9/11, and we went to take on those who had attacked us on 9/11, and to make sure that Afghanistan would not again become a haven for terrorism directed at the United States or any of our allies and partners," Blinken said. "And we achieved the objectives that we set out to achieve."

Through journalistic intermediaries, CNN stringer Saleem Mehsud reached out to al Qaeda for its reaction to Biden's move to pull out troops from Afghanistan, and rather than ignore him as it has done so many times in the past, representatives answered.

Their reply suggests the Taliban is being less than honest with Biden's administration, and that the US troop drawdown could be based on a sham.

CNN has reached out to the Taliban for comment on its relationship with al Qaeda, but it has not responded, rendering al Qaeda's response to CNN a significant insight to what may happen after US troops pull out.

Peter Bergen, CNN terrorism expert and author of several books on Osama Bin Laden, read al Qaeda's reply to CNN and judged it "genuine."

Bergen points to another part of al Qaeda's response highlighting continuing ties with the Taliban, in which it said: "At the same time TTP [Pakistani Taliban] and AQ have relations of Islamic brotherhood which was and still intact and same is the case with the Afghan Taliban."

He notes, "This confirms what the UN has been saying that, 'the Taliban regularly consulted' with al Qaeda during its negotiations with the United States while guaranteeing that they 'would honor their historical ties' with the terrorist group."

Somewhat ambiguously, al Qaeda also claims no interest in using Afghanistan itself as a launch pad for future attacks because it no longer needs it. "It did not need Afghanistan and there is no such intention in the future," the group says. However, as Cruickshank points out, "a statement of intent from an anonymous operative is hardly binding on the group."

Terror group eclipsed by ISIS

In its reply to CNN al Qaeda declares Afghanistan its victory. "The Americans are now defeated," and draw a parallel to the Soviet Union's withdrawal three decades ago from the country and its subsequent collapse: "The US war in Afghanistan played key role in hitting US economy."

That line echoes the rhetoric of bin Laden himself, who promoted the oversimplified idea that the Soviets bankrupted themselves in Afghanistan. The cost of the US wars on terror has reached into the trillions, but the 9/11 attacks did not bring on US economic collapse. Al Qaeda admits the toll the war has taken on them, saying it sent "most" al Qaeda central fighters to Syria where "some of them have been martyred in recent years."

It also admits that bin Laden's death at the hands of Seal Team 6 did weaken al Qaeda, allowing the more nihilistic Islamists, ISIS (Daesh), to become established. "They benefited from the martyrdom of Sheikh Osama, Sheikh Atiyahullah, Sheikh Abu Yahya Al-Libi (may God have mercy on them) and many others."

In recent years ISIS's atrocities and attacks it inspired in Europe have all but eclipsed al Qaeda. But the latter presents this as a "tactical silence," claiming it is not "broken" and is instead "fighting a long war" with "different stages."

Bergen says, "This fits with the [bin Laden] documents in Abbottabad in which AQ leaders treat TTP as a junior partner who they can boss around (even though AQ is a tiny organization and the TTP a large one, relatively speaking)."

"But make no mistake -- the terrorist threat has evolved beyond Afghanistan since 2001 and we will remain vigilant against threats to the United States, wherever they come from. Al Qaeda and ISIS are in Yemen, Syria, Somalia, and other places in Africa and the Middle East and beyond."

Afghanistan could be free for al Qaeda again

Today al Qaeda appears proud of its influence over the TTP. "Now the organization of Pakistani Taliban and their leadership not only moving forward in the light of Sharia but also making better decisions based on past experiences and recent successes have been made possible by the same unity and adherence to Sharia and Wisdom."

It's unclear if this is a reference to the TTP's first major assault in several years in which it struck a hotel where the Chinese ambassador was reported to be staying in Quetta last week. Pakistani security officials tell CNN that China's ambassador was not the target, but even so it highlights that al Qaeda is regaining strength.

If the Taliban is as close to al Qaeda as that group claims, and the UN assesses, then AQ's 2,000-word communication with CNN implies that rather being ceasefire partners with the US, the Taliban is as close to abetting al Qaeda in war against America as it ever was.

Al Qaeda is making clear the country that was once its base to plan the deadliest-ever attack on American soil is free for it to use again. "The United States is not a problem for our Afghan brothers, but due to the sacrifices in the Afghan war, the Americans are now defeated. Whether Republicans or Democrats -- both have made final decision to pull out from the Afghan war."

If the Taliban keeps its promises to Biden, then all this is just al Qaeda propaganda, but if it doesn't, all bets about the future threat it poses are off.

This story has been updated.