This paper develops and tests five hypotheses regarding the economic causes of complex humanitarian emergencies (CHEs). We argue that: (1) such emergencies, involving large-scale deaths and population displacements, are most likely to occur when growth is slow, negative, or falls far short of expectations; (2) the likelihood of emergency rises further when society cannot achieve a consensus over how to distribute the burden of adjustment to this growth failure; (3) the difficulties of burden-sharing are aggravated when there are sharp pre-existing class and/or ethnic inequalities, some of which may have actually helped trigger the crisis by creating conflict and thereby slowing growth; (4) problems are exacerbated when external actors intervene on one side in the ongoing distributional struggles; and (5) the resulting social upheaval deters investment and slows growth, setting in motion in a 'vicious circle' in which political and economic crises exacerbate each other. The civil wars of the 1980s in the Central American countries of El Salvador, Guatemala, and Nicaragua provide evidence in support of each of these hypotheses. Longstanding tensions arising from deep economic inequities, particularly in the distribution of land, provided the tinder for political violence, macroeconomic crises added a spark, external intervention fueled the wars, and armed conflict propelled a downward economic spiral. The paper develops these themes with a particular focus on the case of El Salvador. An understanding of these causal chains is important not only to improve the international community's ability to anticipate complex humanitarian emergencies, but also to devise successful post-conflict economic policies for building peace. Peace accords can initiate a 'virtuous circle,' in which the consolidation of peace supports economic development and vice versa. For this positive process to be sustained, domestic and international actors must confront the fundamental factors behind conflict-driven emergencies. While a more active role by external assistance actors may appear to intrude on national sovereignty, CHEs are often human-made disasters that impose high costs on the international system; as such, the international community has a responsibility to act to address the root causes of civil conflict and the resulting emergencies.