Since declaring a caliphate in summer 2014, ISIS has experienced a seemingly meteoric rise in public attention, stealing daily headlines across the globe. They have taken focus and attention away from Al-Qa'eda, whose name has widely disappeared from the public sphere(1). This is a mistake. Less noticed and considered less dangerous by some, Al-Qa'eda actually represents a far greater threat.
Historically intertwined with common roots ISIS and Al-Qa'eda became bitter rivals following a violent divergence in 2013. But both groups are highly dangerous and ideologically committed to the founding of a global Islamic caliphate and destruction of anybody that disagrees with them. They differ only on when the Caliphate should be founded: Al-Qa'eda believing that (not unlike Russia's Mensheviks) an Islamic Caliphate can only come about through organic revolution of all Muslim peoples. ISIS meanwhile argues (like the Bolsheviks) revolutionary state-building can create the Caliphate now. This crucial disagreement led the groups to split.
Since then, both have increasingly sought to establish themselves in Syria. And here Jabhat Al-Nusra (the Syrian Al-Qa'eda affiliate) is winning. As Charles Lister has demonstrated, al-Nusra holds widespread popularity amongst the Syrian people. With deep roots and a strong track record, al-Nusra is able to recruit freely, hide amongst the public, and even enjoy not inconsiderable support from parts of the Free Syrian Army (FSA) - who will be key to defeating regional jihadists. ISIS by contrast is widely reviled, under attack from just about everybody, and even witnessing defections of its own soldiers to al-Nusra. ISIS faces a considerable challenge to its existence in Syria in a way that Al-Qa'eda simply does not.
And this challenge is starting to show. Although it controls swathes of oil-producing Syria and Iraq; accesses secure tax revenues from Mosul, Raqqa, and elsewhere; and still draws foreign fighters from ever more diverse locations, ISIS is starting to be on the back foot.
Despite significant gains in the population-rich, predominantly Sunni areas of Western Syria during 2015, the loss of Ramadi marks the latest in a string of setbacks for the group. Economically ISIS is under pressure. While structuring itself as a bureaucratic state gives ISIS the ability to finance a hefty military budget via taxes, this structure also makes the group dependent upon its economy and necessitates the group has features of a state such as a permanent physical presence that is not easily concealed. This requires ISIS to fight like a conventional army; a dangerous tactic in the face of better-armed enemy states.
Coalition airstrikes are cutting the group's oil revenues, forcing ISIS to reduce its' fighters salaries and increasing the risk of a civil revolt. Economic malaise is further highlighted by a failed attempt to issue a currency and by the floundering efforts to replace lost revenues by attempting to seize opium production from the Afghan Taliban. In short, ISIS is beginning to lose the means to finance itself; arguably the key to the group's demise.
Al-Qa'eda on the other hand faces no such problems. With little prospect of a popular uprising, attack from few sides, and low operating costs, its modus operandi makes them far harder to eradicate. In contrast to ISIS, Al-Qa'eda adopts the structure of a somewhat diffuse guerrilla insurgency: allowing its fighters to melt into the civilian population at will; make them far harder to locate; and significantly less dependent on finance. The result is that it is much harder to go after al-Nusra. Members are difficult to identify and there are no easy targets for economic strangulation. Al-Nusra is much harder to attack, and it can survive a protracted conflict in a way that ISIS cannot.
The only way to attack Al-Qa'eda will be for the Syrian people to root them out; as happened in the Iraqi Sah'wa (awakening) of 2006/7. This is not likely to happen soon. Unlike Al-Qa'eda's then presence in Iraq (the so-called Islamic State in Iraq), the local people do not revile al-Nusra, and the group has learnt from the mistakes of other Al-Qa'eda affiliates. It will not risk alienating the local population through excessive brutality any time soon. So long as this does not change Al-Qa'eda will be very difficult to defeat.
All this shows that, despite lacking the media spotlight, Al-Qa'eda is significantly more dangerous than ISIS. Facing little resistance, broad support, and a structure optimised for combatting enemy states, Al-Qa'eda is growing and will long outlast ISIS. Throughout this time they will continue in the same ambition as ISIS to destroy anything perceived as an enemy of Islam - be it Assad or Western governments and people. The international community must not make the grave error of failing to address the on-going threat posed by Al-Qa'eda.