After the failure of its strategy to overthrow President Assad between 2011 and 2015, Turkey has become a more significant player in the Syrian civil war from 2016 onwards. It has effectively resurrected the Syrian armed opposition as viable fighting force by gradually establishing centralised control over, and professionalizing, many Syrian National Army (SNA) as well as National Liberation Front (NLF) groups, on occasion even going as far as partnering with ‘pragmatic’ Hey’at Tahrir al-Sham elements (HTS; a former Al-Qaeda affiliate) (see Figure 1) in order to establish a Turkish sphere of influence in northern Syria.

Key variables that have influenced the effectiveness of Turkey’s engagement with different sets of armed Syrian opposition groups include: a) the possibility of obtaining influence by providing significant material support, such as training, salaries and equipment; b) the extent to which it could partner such groups with its own military (based on shared culture, perceived enemy and ideology); c) the level of centralised control it was able to achieve; d) geographic proximity; and e) clever divide-and-rule tactics, which, alongside relative neglect of ideological differences, proved useful in tipping these variables in Turkey’s favour.

The main effect of Turkey’s proxy warfare strategy is that it has effectively resurrected the ‘revolutionary’ cause (toppling Assad) of Syria's civil war, albeit now under strong Turkish influence and with a powerful undercurrent of national Islamism. This will ensure long-term Turkish influence in northern Syria via an array of ‘secular revolutionary armed groups’ and ‘nationalist Islamist armed groups’ (see Figure 1). Such influence is currently being expanded east of the Euphrates river. While Turkey’s strategy was successful in Afrin (north-west Syria) and the Al‍-‍Bab ‍- Jarabulus area (north Syria), it remains work in progress east of the Euphrates river, and limited in Idlib (north-west Syria) by HTS’s historical affinity with Al-Qaeda, the group’s independence and the personality of its leader.