PARIS -- To the uninitiated, "Islamic State of Iraq and Syria" (ISIS) and al-Qaeda may appear to be pursuing the same long-term goal of spreading Sharia law through territorial expansion and deadly violence.
However, their ideologies and methods in reality differ so fundamentally that they are increasingly turning on each other.
Last month, ISIS in West Africa released a video showing its men butchering fighters presented as members of Jamaa Nusrat ul-Islam wal-Muslimin, an al-Qaeda franchise, in Mali.
Fifty-two were killed.
Fighting between rival insurgents has claimed the lives of some 300 "jihadists" in the Sahel region of West Africa since July alone, according to Mohammed Hafez, a professor at the US Naval Postgraduate School in Monterey, California.
The reasons for the fighting range from control of territory or profitable trafficking corridors to filling power vacuums left behind when local leaders are killed.
"The civil war raging between global jihadis is intensifying," wrote Hafez in the CTC Sentinel journal of the US Military Academy's Combating Terrorism Centre.
"These dueling factions have failed to overcome the challenge of fragmentation under the stress of conflict and territorial retreat," he wrote in the CTC Sentinel journal of the US Military Academy's Combating Terrorism Centre.
"They turned their attention away from near and far enemies and instead prioritized fighting the nearest enemy of all -- each other."
Hearts and minds
ISIS arose from the ashes of an al-Qaeda offshoot, al-Qaeda in Iraq, which was largely decimated by US-led forces backed by local militias in the mid-2000s.
But ISIS immediately took a different course from that of al-Qaeda -- which until then had been the West's public enemy number one because of the 9/11 attacks in the United States.
Whereas al-Qaeda views the destruction of the West as a prerequisite for the establishment of an Islamic state, ISIS set out to establish a caliphate in "liberated territories" from which to launch its war of conquest, geopolitical researcher Nathanael Ponticelli wrote in the journal of the French Institute for International and Strategic Affairs.
ISIS was uprooted last year from the "caliphate" it proclaimed in Syria and Iraq in 2014. It also sought to establish roots in Afghanistan through its Khorasan branch (ISIS-K), but Afghan and US forces prevented the group from taking hold.
Al-Qaeda has sought to position itself as an "inclusive, pragmatic and populist pan-Islamist movement", whereas ISIS represents "an exclusive, uncompromising and puritanical vision of jihadism", wrote Hafez.
ISIS claims exclusive legitimacy to punish "takfirs", Muslims considered to have strayed from the teachings.
Although al-Qaeda "and other Islamists seek to work hand-in-hand with their beleaguered populations in order to win their hearts and minds, [ISIS] cares little about populism and instead advances an exclusive, vanguardist vision that seeks to mould hearts and minds through the divine imperative to command the good and forbid vice", said Hafez.
In April, ISIS issued a 52-minute video pointing out what it says are instances of al-Qaeda's deviance from scripture.
"The self-declared caliphate has developed a significant institutional hatred for al-Qaeda," Thomas Joscelyn of The Foundation for Defence of Democracies, a Washington think-tank, told AFP.
"It is always possible that some factions within each group are currently working together, or they will do so in the future. But the video indicates that a grand reconciliation between the two jihadist rivals is unlikely in the near future."
In December 2018, al-Qaeda made similar claims against the then-ISIS leader, the "deviant" Abu Bakr al-Baghdadi, calling on Muslims everywhere to rise up and destroy the group.
Al-Baghdadi died during a US-led raid in Syria in October 2019.
No shortage of fighters
But, say observers, the Western world should not take comfort in the two militant groups being at each other's throats.
Much can be trampled in their battle for supremacy, territory, followers and media attention, they warn.
"Since 9/11, the problem of violent jihadis has grown in scale, scope and violent magnitude -- all this despite being divided and pursued by a super power, multinational coalitions and local governments," wrote Hafez.
"Whereas in the past the international community was dealing with one global jihadi movement headquartered in Afghanistan, today there are two with branches that span several regions and countries."
Furthermore, the militants have proven they can "plan operations and fight their adversaries even as they are killing each other", said Hafez.
For Elie Tenenbaum, a researcher at the French Institute of International Relations, the two groups are seeking to outdo each other -- and neither is likely to run out of fighters.
"By fighting, the groups consolidate their domination and even conquer new territories," he told AFP.