"The enemy of my enemy," goes the old adage, "is my friend".

It's a popular quote that is often misattributed to the Arabs and yet, ironically, nowhere is it less true than in the Arab world.

Take Syria. What began as a non-violent, Arab Spring-inspired revolt against the tyranny of Bashar al-Assad's Baathist regime in 2011, soon morphed into a violent insurgency - provoked by the brutal government crackdown on peaceful protesters followed by the use of barrel bombs and even chemical weapons against civilian targets.

From the very beginning, the armed rebel movement included those who wanted to build a post-Assad, non-sectarian democracy.

Yet, as long ago as 2012, a secret report by Pentagon officials acknowledged that al-Qaeda in Iraq (AQI) was one of the "major forces driving the insurgency in Syria".

Today, the Nusra Front, an offshoot of AQI which announced its presence in Syria at the start of 2012 and took responsibility for a succession of suicide bombings in 2011, is at the vanguard of rebel-led clashes with both pro-Assad security forces and the fanatics of the so-called Islamic State of Iraq and the Levant (ISIL).

Rebranding Nusra

Having been officially designated as a "foreign terrorist organisation" by the US state department back in December 2012, due to it being "an alias for al-Qaeda in Iraq", in recent months there have been several reports suggesting the Nusra Front is trying to "rebrand" and present itself to the Syrian people, not to mention pro-opposition outside powers such as the US, as a more moderate, "purely Syrian force not linked to al-Qaeda".

Should we take this rebranding exercise seriously?

Some analysts do seem to believe the Nusra Front could be a useful partner in the struggle against both Assad and ISIL.

"The West currently sees the Nusra Front as a threat," wrote Carnegie's Lina Khatib in March.

"But Nusra's pragmatism and ongoing evolution mean that it could become an ally in the fight against [ISIL]."

Syrian journalist Ahmad Zaidan, Al Jazeera Arabic's Pakistan bureau chief, believes "the international community must respond to the realities on the ground" and "the verdict on Nusra is not out yet".

Plenty of human rights groups and counterterrorism experts, however, disagree.

Consider the evidence amassed by Human Rights Watch, in a lengthy report on Syria earlier this year.

The Nusra Front, concluded HRW, was "responsible for systematic and widespread violations including targeting civilians, kidnappings, and executions".

For all the talk of evolution, pragmatism and moderation, it is difficult to come to any other conclusion than that the Nusra Front is a front for al-Qaeda, plain and simple.

Like ISIL, the group has "committed systematic rights abuses, including the intentional targeting and abduction of civilians" with "repeated claims of responsibility for lethal car bombing attacks that have targeted civilians in Syria".

The Nusra Front, HRW added, has - again, like ISIL - "imposed strict and discriminatory rules on women and girls and they have both actively recruited child soldiers".

So, a moderate or pragmatic group then? Not by any stretch of the imagination.

Comparatively moderate?

In fact, one of the main reasons this line of argument is pushed - and indulged - by a growing number of commentators is because of the "oft-repeated belief", in the words of the New York-based security consultancy, The Soufan Group, "that [ISIL] is too violent for AQ and JN [the Nusra Front], and that JN therefore must be comparatively moderate".

As a briefing by The Soufan Group - founded by former FBI agent and al-Qaeda expert Ali Soufan - noted in January 2015: "This notion that JN [the Nusra Front] isn't as violent as [ISIL] is wrong; both groups follow the extremism of bin Ladinism, though the former uses a bullet while the latter prefers a blade - or worse."

The briefing continued: "Indeed, in mid-January [ISIL] produced a video of its members stoning a woman to death for the alleged crime of adultery; the same week JN [the Nusra Front] released a video of its members shooting two women to death for the same alleged offence - stylistic differences applied to the same violent ideology and goals."

This point about a common ideology, and goals, cannot be overstated. To be clear: the Nusra Front wants to set up a caliphate, too. It wants to impose a barbaric and brutal form of Islamic law, too. The Nusra Front targets religious minorities, too.

Writing in the Huffington Post in May, Charles Lister, a visiting fellow at the Brookings Institution, Doha, and the author of a forthcoming book on the Syrian insurgency, pointed out how the group has been "unilaterally imposing a harsher level of sharia justice", including "stoning men and women to death" and "restricting women's dress and freedom of public movement", in the Syrian territories under its control since the end of 2014.

In a recent, rare and exclusive interviewwith Al Jazeera Arabic, the leader of the Nusra Front, Abu Mohammed al-Golani, tried to present a more moderate image to the world by pledging not to carry out attacks against the West and dismissing the ISIL's self-proclaimed caliphate as "illegitimate" and "not based on Islamic law".

Disturbing declarations

Nonetheless, he couldn't resist making two rather disturbing declarations (admissions?). First, he warned members of the pro-Assad Alawite minority within Syria that they would be safe from the Nusra Front only if they: abandoned the regime, repented for their actions and, crucially, "return[ed] back to the Islamic faith".

In the interview, Golani makes it clear that he doesn't consider them to be Muslims - or, at least, not his type of Muslims.

Nor does he say he'll leave them be, unless and until they convert to (his brand of) Islam. To quote the Syrian Islamic scholar and anti-Assad activist Sheikh Muhammad al-Yaqoubi, Golani's approach to the Alawites is "they should become Muslims and 'then we will accept them'… Golani's position means that Alawites have ... only the choices of converting to Islam or being killed".

Second, despite all the press reports earlier in the year suggesting the Nusra Front was on the verge of cutting its ties with "al-Qaeda Central Command", Golani repeatedly reiterated his own allegiance to Ayman al-Zawahiri, the mass-murdering leader of al-Qaeda.

"We abide by the guidelines of Dr Ayman, may Allah protect him," he told Al Jazeera Arabic, while sitting in front of a table with an "al-Qaeda in the Levant" flag planted on it.

For all the talk of evolution, pragmatism and moderation, it is difficult to come to any other conclusion than that the Nusra Front is a front for al-Qaeda, plain and simple.

As Lister argues, the group "must still be viewed as an avowed member of al-Qaeda" and "should the Assad regime one day fall or be pushed aside in a negotiated political transition, al-Qaeda's true colours will surely be revealed".

Thus, Zaidan is correct when he writes that the biggest challenge in a future, post-Assad Syria will be "how to accommodate everyone in tolerance and to build bridges to unite the shattered country".

The problem is that al-Qaeda isn't known for its tolerance; it specialises in blowing up, rather than building, bridges. That's why the phrase "moderate al-Qaeda" has always been a bit of an oxymoron.

And that's also why opposing Assad, or ISIL, shouldn't require supporting the Nusra Front … aka al-Qaeda. As is so often the case in the Middle East, the enemy of my enemy can also still be my enemy.

Mehdi Hasan is an award-winning British journalist, author, social commentator and the presenter of Head to Head.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.