Among the main regional sponsors of the Syrian rebels, Saudi Arabia had the clearest idea of the shape the insurgency should take, or more exactly should not take. Indeed, besides anti-Iranian geopolitical calculations and a quest for domestic legitimacy, it seems that Riyadh’s decision to start providing support to Syrian insurgents in the spring of 2012 was sparked by an anti-Islamist stance, and more specifically by the growing influence of factions closely tied to the Muslim Brotherhood and/or Qatar, [...] Lebanese intermediaries first appointed by the Saudis to distribute aid to the Syrian rebels, such as Mustaqbal MP Uqab Saqr, were given a mandate that one of their Syrian interlocutors summarised as follows: “help anyone but the Islamists.”
 
One of the first rebel factions to benefit from Saudi largesse were the Faruq Battalions in Homs, an FSA flagship that during the first year of the insurgency was perhaps the most powerful and wealthiest insurgent group in Syria. [...] Besides its multiple and shifting loyalties, Faruq also disappointed Saudi Arabia (and its other patrons) with its organisational dysfunctions. The group’s leadership was an ad hoc collection of military defectors (Lt. ‘Abd al-Razzaq Tlass), civilian revolutionary activists (Hamza al-Shamali) and religious clerics (Amjad al-Bitar) that had joined forces after 2011.
The loose character of al-Faruq’s command structure was further exacerbated when the group used its considerable purchasing power to expand in the north of the country, where it acquired even more resources and made itself an essential partner to Turkey by taking control of border crossings. [...] By mid-2013, Faruq had become a minor faction, and within a year further internal disputes destroyed what was left of the group.

A considerable amount of Saudi money was also spent on the Ahfad al-Rasul Brigades, a nation-wide alliance run by military defectors that in the first half of 2013 seemed able to compete with the largest Islamist coalitions.
Like the Faruq Battalions, Ahfad al-Rasul was initially appealing enough to secure funding from both Qatar and Saudi Arabia, but also like Faruq its leadership was based on loose (partly tribal) networks that proved dysfunctional and made the alliance unable to resist successive onslaughts on the part of Jihadi rivals: in mid-2014 Islamic State destroyed Ahfad al-Rasul’s main strongholds in the Euphrates  valley and at the end of the same year the Nusra Front annihilated the northern branch of the Syria Revolutionaries Front, the product of an earlier merger between Ahfad al-Rasul and Jamal Ma‘ruf’s Martyrs of Syria, another non-Islamist Saudi favourite. Having lost its main assets in northern Syria by early 2015, Saudi Arabia had no choice but to engage in a cautious rapprochement with Ahrar al-Sham, Qatar and Turkey’s main Islamist ally in the area.

Those Saudi partners that proved more resilient in the long term owed their relative success to factors other than funding from Riyadh. In the eastern suburbs of Damascus, the late Zahran ‘Allush’s Army of Islam has not only managed to survive a three-year siege by regime forces, but also to establish itself as the dominant rebel force in the area [...] Yet the Army of Islam is hardly a Saudi creature. A Salafi group, and as such the one major exception to Riyadh’s reluctance to deal with Islamist factions, it once had Qatar-aligned alliances (Syrian Islamic Liberation Front and Islamic Front) and has received support from Surur’s networks.
 
The group’s connection with Saudi Arabia stems from long-standing ties between ‘Allush’s father, a Salafi scholar, and the Saudi religious establishment, but certain Saudi decision-making centres have long distrusted the Army of Islam. In any case, it is the cohesiveness of the group’s organisational structure (itself the result of a closely-knit pre-war semi-clandestine religious network) that has made it such an efficient and hence attractive target for various sources of funding rather than the other way round.

The other main area of Saudi influence is the southern province of Daraa, which is virtually the only place where Riyadh’s preference for a predominantly non-Islamist insurgency has prevailed and persisted in the long run.
 
Southern Front, a broad coalition of FSA-banner factions, remains by far the dominant force in the province with at least twenty-
five thousand fighters as opposed to, probably, a mere four-digit number of Islamist rebels.
This exception results from a combination of factors, among which is a tight control of rebel supply lines by the Jordanian authorities, whose anti-Islamist bias has been even more pronounced than that of Saudi Arabia. In its relations with Syrian rebels, Amman has been advantaged by a sizeable and competent intelligence apparatus that is familiar with southern Syria’s social and cultural context due to geographical proximity. However, even in such ideal conditions there have been limits to what local rebels can achieve in terms of unification

In 2013, Qatar provided the Syrian rebels with a small batch of Chinese-made, Sudan-sourced FN-6 man-portable air-defence systems (MANPADS).
The eight different groups that benefitted from this gesture of generosity before deliveries were interrupted, probably under US pressure, spanned across a broad ideological spectrum including local Military Councils of the Western-backed Free Syrian Army, the Muslim Brotherhood-affiliated Shields Committee, and the hard-line Salafis of Ahrar al-Sham.
This eclecticism reflects a strategy that was primarily shaped by two of the small emirate’s key characteristics: first, in spite of enormous financial means, it has scarce limited institutional and human resources to manage relations with foreign paramilitaries; second, in contrast to other Gulf monarchies, it has a relative indifference to the ideological orientation of foreign partners because of the Alani family’s utmost confidence in the domestic stability of its own rule [...]
 
In spite of this, Qatar’s policy towards the Syrian insurgency has not been uniformly pro-Islamist. As the FN-6 episode illustrates, Doha has also provided support for FSA-affiliates dominated by military defectors. [...] In 2012 and 2013, when FSA structures dominated by army defectors were established (Supreme Military Council, Headquarters, local Military Councils), Qatar worked to match Saudi influence within these structures, and to seize its share of what might then possibly become a major conduit of Western support for the insurgency. [...]

In the meantime, Doha continued to support Islamist factions and by the spring of 2015 emerged along with Turkey as the main sponsor of the Army of Conquest alliance, which expelled regime troops from the province of Idlib
[...] To sum up, Qatar’s policy of support for Syrian rebels was shaped by a combination of opportunities (the availability of non-state intermediaries) and constraints (rivalry with Saudi Arabia, Western pressure). Its utterly pragmatic strategy of wall-to-wall support for insurgent factions allowed Doha to have the best of both worlds as it found itself in a privileged relationship with the Islamist factions that turned out to be the most efficient and resilient components of the insurgency [...]
 
Qatar’s association with such a cohesive and efficient faction as Ahrar al-Sham should not suggest that Qatari funding was the key variable behind their success, since Doha’s support also benefitted factions that proved less convincing in the long term. For instance, the Tawhid Brigade (renamed Levant Front in 2015) [...] However, following the assassination of its charismatic military leader ‘Abd al-Qadir Salih in October 2013, it gradually lost strength as a result of poor discipline and internal factionalism, which in turn entailed a drop in external support. Unlike Ahrar al-Sham, whose core leadership was built upon a cohesive network of Jihadi veterans, many of which had formerly been detained together at the Seydnaya prison near Damascus, Tawhid was a frail coalition of local groups held together by Salih’s charisma, by the short-lived momentum of crushing victories against the regime in 2012, and by foreign, notably Qatari, money. True, other foreign states (SA/US) contributed to the weakening of the Tawhid Brigade/Levant Front by denying it access to MOM-supplied TOW missiles, thereby encouraging the creation of splinter factions[...].
 
This pattern had also been observed the previous year when another Aleppine faction, the Nur al-Din Zanki Movement, secured TOW supplies as soon as it left the Army of Mujahidin, whom Saudi Arabia opposed for its alleged ties to the Muslim Brotherhood.
Yet, it is remarkable that Ahrar al-Sham’s exclusion from the list of the MOM’s  vetted recipients did not prevent its continuous absorption of smaller factions. It seems, therefore, that foreign pressures have had a detrimental effect on the cohesion of rebel factions when that cohesion was already fragile.

Although quantitatively significant, foreign state support for Syrian insurgents has only had a limited impact on the resilience and cohesiveness of its rebel beneficiaries. Once-lavishly-funded factions like the Faruq Battalions, Ahfad al-Rasul Brigades and Tawhid Brigade have disintegrated or dramatically weakened, while others have continued to thrive despite temporary losses of resources, like Ahrar al-Sham, or under dire military and logistical conditions, as in the case of the Army of Islam. In all cases, the independent  variable determining the success or failure of these groups has not been the level of external support they receive, but the nature of their leadership: tightly knit networks of long-standing partners on the one hand, as opposed to loose ad hoc coalitions on the other hand. Likewise, the cases of Daraa and Aleppo show that even when foreign influence was exerted by or through a single hegemonic foreign state patron (Jordan and Turkey respectively) over an ideologically homogeneous insurgent scene, dysfunctions stemming from the fragmented social structure of the rebel leadership proved hard to overcome for foreign patrons.
 
The major policy implication of the developments expounded above is that whatever financial resources state sponsors pour into their insurgent partners, they cannot make a rebel faction successful when its leadership is dysfunctional, nor can they lastingly impose unity on rebel groups against their inherent centripetal dynamics. Such implications were already acknowledged to some extent when the project for a fully integrated ‘Free Syrian Army’ was abandoned in favour of the more modest MOC/MOM approach, with coordination replacing overambitious unity schemes, and support being provided directly to select moderate factions that had survived the Darwinian selection process of the war. Scaling down their aims of shaping a foreign insurgency is probably the most realistic strategy for states that lack both a militant ideology to export and a fully-fledged agency designed for propping up foreign insurgents who embrace that ideology – that is,  virtually all regimes except revolutionary ones