Of all the places where Turkey and Qatar support extremists, the two have done the most damage in Syria. Since the beginning of the civil war that erupted in 2011, Qatar and Turkey have worked to establish joint patronage of Sunni opposition groups bent on toppling the regime of Bashar al-Assad. Qatar has provided arms and financing to his opponents, while Turkey has assisted with training and logistics. By early 2012, Qatar was reportedly flying arms to Turkey, where the Turkish intelligence services helped deliver them across the border. The Qataris reportedly relied on Turkish intelligence and exiled Muslim Brotherhood members to identify recipients.

Underpinning Turkish support is the AKP’s ideology, which holds that secular Middle Eastern regimes should be replaced by governments that more accurately represent the region’s “Muslim majorities.” Yet Turkish priorities shifted in response to the rise of Syrian Kurdish autonomy, which Ankara sees as a threat to Turkey’s efforts to contain its own separatist Kurdish insurgency. Following the advances made by U.S.-backed Kurdish forces in Syria, Turkey has recalibrated its policy: While Ankara continues to support an array of extremist militias fighting Assad, it is now focused primarily on preventing the establishment of a Kurdish statelet along the Turkish-Syrian border.

Qatar, meanwhile, threw its weight behind Syrian Islamist groups as part of its broader Arab Spring policy of supporting popular uprisings that could enable “friendly Muslim Brotherhood-aligned governments,” as Christopher Phillips notes, to take control, thus boosting Qatar’s regional influence. This policy initially put Qatar at odds with Saudi Arabia, which at the war’s onset supported only the Free Syrian Army (FSA) and secular groups. Yet Saudi Arabia shifted its policy after Iran increased its involvement in Syria. As Yehuda Blanga points out, Riyadh then “became willing to support Salafi groups and cooperate with Qatar.”

In Turkey in 2011, Syrian army dissenters founded the FSA, a loose network of brigades fighting the Assad regime. Since 2011, the group’s leadership has been based in Turkey, where the government has allowed the FSA access to supply lines running into Syria. Some FSA groups received training from Turkey as well. Factions within the FSA work with hardline extremists, including al-Qaeda-linked jihadists and Ahrar al-Sham. Jihadist groups also have opportunistically partnered with FSA factions to fight rival extremist outfits.

In 2012, Turkey set up a “nerve center” in Adana, roughly 60 miles from the Syrian border, through which Ankara and Doha funneled weapons and communications assistance. Between 2012 and 2013, Qatar sent more military cargo planes to Turkey to arm Syrian rebels than did any other country involved, according to reporting by The New York Times. In 2016, Qatar doubled down on its support for the rebels, vowing to keep arming them even if the United States pulled its support.

Some FSA elements participated in the Turkey-led Euphrates Shield offensive against the Islamic State and Kurdish groups in northern Syria. During the operation, which began in August 2016, groups within the FSA received direction from Turkey and pivoted from fighting Assad’s forces to attacks against the Kurds and the Islamic State.

In May 2018, Turkey created the “National Liberation Front,” composed of nearly 10 FSA factions along with Ahrar al-Sham and Harakat Nour al-Din al-Zenki, another extremist militia. Turkey also sought the participation of Jabhat al-Nusra – which by 2016 had rebranded as Jabhat Fateh al-Sham before merging with several other jihadist groups to form Hay’at Tahrir al-Sham (HTS) in 2017 – but the group refused to join. Turkey’s efforts to consolidate these rebel groups stemmed largely from its desire to exercise “stronger command and control.”

Turkey’s state intelligence agency (MIT), meanwhile, seems to have a regular relationship with the al-Qaeda-aligned Jabhat al-Nusra, even after Ankara reluctantly designated al-Nusra as a terrorist group in 2014. According to testimony from Turkish gendarmes, rocket parts, ammunition, and semi-finished mortar shells were carried in trucks accompanied by MIT officials to parts of Syria controlled by Nusra in 2013 and 2014. Weapons and money sent to less extreme Islamists have also made their way to al-Nusra and other extremist groups. Qatar and Turkey likely turned a blind eye to these diversions because these groups were generally more effective against the Assad regime.

In March 2015, a number of Sunni Islamist militias including al-Nusra, Ahrar al-Sham, and the Muslim Brotherhood affiliate Sham Legion began joint operations against the Syrian regime, under the name of Jaish al-Fatah (Army of Conquest). Al-Nusra reportedly led the coalition. The emir of Qatar reportedly brokered the formation of Jaish al-Fatah with Ankara’s encouragement. The umbrella organization took control of Idlib province in March 2015 and began receiving funding from Qatar, Turkey, and Saudi Arabia.

In August 2016, two rebels told the Financial Times that Qatar and Saudi Arabia were consistently delivering cash and supplies to Aleppo via trucks routed through Turkey, to support a military offensive against the regime by al-Nusra (which by that point had rebranded as Jabhat Fatah al-Sham).

Ankara and Doha also supported al-Nusra by granting impunity to individuals and charities in Turkey and Qatar that raised funds for the group. In 2014, then-Undersecretary of Treasury for Terrorism and Financial Intelligence David Cohen called Qatar a “permissive jurisdiction” for terror financiers who raised funds for al-Nusra and the Islamic State, among others. Cohen’s successor, Adam Szubin, said Qatar lacked “the necessary political will” to crack down on terror financing.

Kuwaiti preacher Hajjaj al-Ajmi provides a case in point. Ajmi is under sanctions by the United States, United Nations, Bahrain, Saudi Arabia, and the UAE on charges of funding al-Qaeda in Syria. He was accused of directing his followers to donate money through the Turkey-based Kuveyt Turk Participation Bank, although his U.S. district court case was ultimately dismissed for jurisdictional and standing issues. He reportedly called for arming Syrian jihadists while on a trip to Qatar sponsored by the Qatari government. When the United States designated Ajmi in 2014, he was reportedly on another trip to Qatar.

In 2015, the United States and United Nations placed two Qatari nationals, Sa’d bin Sa’d al-Ka’bi and ‘Abd al-Latif bin Abdullah al-Kawari, under terror finance sanctions; the anti-Qatar quartet followed suit in sanctioning them in 2017. Ka’bi and Kawari served as leaders of a Qatar-based fundraising campaign for Syrian humanitarian relief called Madad Ahl al-Sham (MAS), which reportedly also raised funds to arm Syrian fighters. In a Twitter message that MAS itself retweeted, al-Nusra endorsed the MAS campaign in 2013 as “one of the preferred conduits for donations intended for the group,” according to The Washington Post. According to the U.S. Treasury Department, Ka’bi “set up donation campaigns in Qatar to aid with fundraising in response to a request from [an al-Nusra] associate for money to purchase both weapons and food.”

MAS reportedly worked under the umbrella of a quasi-governmental Qatari institution to send donations via Turkish and Jordanian territory. A video posted by a Turkish charity in 2014 appeared to promote its work “in cooperation with the [MAS] campaign” in Turkish territory.

A wide array of publications have also accused Doha of indirectly financing al-Nusra through ransoms. Turkish columnist Yusuf Kanli wrote in October 2013 that Qatar helped negotiate the release of two Turkish pilots who were flown home from Lebanon on a Qatar Airways plane in exchange for nine Shi’ite pilgrims held by al-Nusra in Syria. Kanli alleged that Qatar paid a $150 million ransom to al-Nusra as part of the exchange.

A Lebanese security official said that “the $150 million figure seemed high” but acknowledged that “the deal did include money paid by Qatar.” Qatar’s then Foreign Minister Khalid al-Attiya personally negotiated the deal with the Syrian rebels.

In 2014, press reports alleged that Qatar had paid millions of dollars in ransoms to al-Nusra for the release of Syrian nuns, the U.S. journalist Peter Theo Padnos, and 45 Fijian peacekeepers. The emirate reportedly also played an important role in hostage talks with al-Nusra that resulted in the December 2015 release from Lebanon of some of al-Qaeda’s most important prisoners. One of the prisoners, the ex-wife of Islamic State leader Abu Bakr al-Baghdadi, said she would be going to Turkey as part of the deal, despite having helped finance terrorists. Another concession granted to al-Nusra as part of the deal permitted the extremist group to send its wounded to Turkey for medical treatment, according to Al-Jazeera.

In May 2016, al-Nusra released Spanish reporters Angel Sastre, Antonio Pampliega, and Jose Manuel Lopez after 10 months of captivity. The Spanish government thanked Ankara and Doha for their role in the release, which was reportedly brokered after six meetings in Turkey and Qatar. According to the pro-regime Turkish daily Yeni Şafak, the deal entailed a ransom of $3.7 million per reporter as well as an unspecified amount of “humanitarian aid” on the Syrian side of the Turkish border.

In April 2017, Qatar may have paid the largest ransom in history – nearly $1 billion – to secure the release of Qatari royal family members kidnapped in Iraq while on a hunting trip. Nearly $400 million of the total reportedly went to Kataib Hezbollah, an Iran-backed Shiite militia in Iraq. According to the Financial Times, nearly $120 million to $140 million of the $1 billion total went to HTS, with an additional $80 million going to Ahrar al-Sham.

Until 2017, Ahrar al-Sham was one of the closest allies of al-Nusra in Syria. Authorities stopped short of labeling the former group as al-Qaeda, however, thanks in part to a re-branding campaign on the part of Turkey and Qatar.

Turkey began sending arms and money to the group in 2015. Turkish and Qatari NGOs have also reportedly backed Ahrar al-Sham via their joint aid for the Syrian Islamic Front (SIF), a Salafist umbrella organization Ahrar al-Sham dominated. SIF reportedly received money and humanitarian goods from Qatar’s largest NGO, Qatar Charity, as well as from Turkey’s IHH, allowing SIF to increase its legitimacy through the provision of public services. IHH and Qatar Charity have very close ties, and in December 2015, the two organizations signed a partnership agreement in Syria.

Ahrar al-Sham and HTS turned against each other in July 2017, demonstrating the limits of Turkish and Qatari influence, despite their long-standing patronage. Ahrar al-Sham and HTS battled each other for supremacy in Syria’s last rebel-held province, Idlib. HTS prevailed. Fighting briefly reignited in January 2018 but ended with another HTS victory. Following the escalation, Ankara maintained support for Ahrar al-Sham against HTS in Idlib, until the former merged with the Nour al-Din al-Zenki Movement in February 2018 to form the Syrian Liberation Front.