Initially, the Salvadoran state entirely controlled the regions under analysis. In 1981, the guerrillas conducted a countrywide offensive against 12 main military bases in a bid to promote an insurrection (MINED, 2009). Although this failed, it prompted a change in military strategy and thus the group’s geographic dispersion with the goal of establishing a presence on all fronts through the aforementioned _liberated zones_ . The first of these was organized as early as 1982 (Casta ̃neda, 2016). _Liberated zones_ are a key guerrilla warfare tactic and comprise areas where insurgents can generate support by providing basic public goods and establishing their own institutions. The concept dates back at least to Mao Zedong’s military strategy in which _base areas_ were a winning tactic against a conventional army. They consisted of local strongholds in (preferably) mountainous areas where insurgents could elicit popular support by creating systems of governance (Mao, 1966). As this idea evolved, the strategic location of these zones in mountainous areas remained important and it has been copied by non-state armed actors ranging from communist guerrillas in Guatemala in the 1980s (Moran, 1985) to ethnic armed organizations in Burma in 2021.<sup>12</sup> Importantly, historical evidence and FMLN documents suggest that after 1984, the boundaries of FMLN-controlled areas were extremely stable for at least two reasons. First, by 1984, the FMLN controlled approximately 80 percent of the militarily strategic territory (FMLN, 1984). Second, by that same year, more than 80 percent of the Salvadoran Army’s offensive capacity was in permanent use. Therefore, they could not reconquer areas under FMLN occupation but instead had to strengthen the defense of areas the state still controlled (FMLN, 1984). Hence by 1985, the conflict had effectively entered a virtual stalemate (Casta ̃neda, 2016). As a result, we focus on guerrillacontrolled areas that were stable between 1985 and 1992. Figure 1 shows the three strips of the country where the FMLN had full control by 1985: the northern, central, and coastal areas.<sup>13</sup>

# **II.C Rebel governance in FMLN-controlled areas**

Our study region experienced significant cultural, social, and economic transformations during FMLN control. As mentioned in Section II.B, the creation of systems of governance to win over local populations is a fundamental part of rebel strategies that can leave profound changes in their wake. As Wood (2003) emphasizes, rebel control in El Salvador left a legacy of new values, norms, economic practices, and beliefs that contrasted sharply with the prevailing culture before the war

> 12Several cases of self-governing institutions can be found in varying locations throughout history, including the Democratic Republic of the Congo, South Sudan, Liberia, Indonesia, Bolivia, Colombia, El Salvador, and Guatemala. See Arjona, Kasfir and Mampilly (2015) for an analysis of some of these case studies.

> 13The absence of an FMLN presence in the western region is usually attributed to the legacies of the massacres of indigenous peasants by state and paramilitary forces in the 1930s (Lauria-Santiago and Gould, 2008).

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