“…External support has been found to impact all aspects of the civil war process from conflict onset (Cunningham, 2016; Regan & Meachum, 2014), to conflict duration (Anderson 2019; Aydin & Regan, 2011; Cunningham, 2010; Roberts, 2019; Testerman 2015), spill-over to interstate conflict (Schultz, 2010), civil war negotiations (Karlén, forthcoming), conflict outcome (Jones, 2017; Lyall & Wilson, 2009; Sawyer, Cunningham & Reed 2017; McKibben & Skoll, 2021; Keels, Benson & Widmeier, forthcoming), conflict recurrence (Karlén, 2017), and democratic transitions (Colaresi, 2014). It shapes the form of contestation (Jackson, San-Akca & Maoz, 2020; Petrova, 2019), its lethality (Heger & Salehyan 2007) as well as levels of civilian abuse (Salehyan, Siroky & Wood, 2014) and sexual violence (Johansson & Sarwari, 2019).…”