Desertion and Collective Action in Civil Wars

This article examines the impact of military unit composition on desertion in civil wars. I argue that military units face an increased risk of desertion if they cannot develop norms of cooperation. This is a challenging task in the context of divided and ambiguous individual loyalties found in civil wars. Norms of cooperation emerge, above all, from soldiers sending each other costly signals of their commitment. Social and factional ties also shape these norms, albeit in a more limited fashion. Hence, unit composition can serve as an intervening variable explaining how collective aims can sometimes induce individual soldiers to keep fighting. Analyzing original data from the Spanish Civil War (1936–1939), I demonstrate that three characteristics of a military unit's composition—the presence of conscripts rather than volunteers, social heterogeneity (whose effect is found to be limited to volunteer units), and polarization among factions—increase the individual soldier's propensity to desert. Unit composition proves at least as important as individual characteristics when explaining desertion. This analysis indicates the usefulness of moving beyond commonly used atomistic understandings of combatant behavior. Instead, it suggests the importance of theoretical microfoundations that emphasize norms of cooperation among groups of combatants.

本文探讨了部队构成对内战期间军人开小差（desertion）行为的影响。笔者认为，若部队无法形成合作规范（norms of cooperation），则其所属军人开小差的风险将显著提升。在内战背景下，个体忠诚往往分化且模糊，这使得构建合作规范极具挑战。合作规范的形成，首要源于士兵之间相互传递彰显自身忠诚度的代价性信号（costly signals）。尽管作用有限，但社会关系与派系纽带同样会对这类规范的形成产生影响。因此，部队构成可作为中介变量（intervening variable），用以解释集体目标在何种情况下能够促使个体士兵继续作战。通过分析西班牙内战（1936–1939）的原始数据，本文证实了部队构成的三项特征会提升个体士兵的开小差倾向：一是部队由义务兵（conscripts）而非志愿兵（volunteers）组成；二是存在社会异质性（social heterogeneity）（研究发现该效应仅适用于志愿兵部队）；三是存在派系极化（polarization among factions）现象。在解释军人开小差行为时，部队构成的重要性至少不亚于个体特征。本研究表明，摒弃学界对作战人员行为常用的原子论解读视角（atomistic understandings）具有积极意义；与之相反，本研究凸显了构建理论微观基础（microfoundations）的必要性——这类微观基础应着重强调作战群体内部的合作规范。