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External Intervention, Identity, and Civil War


  • Nicholas Sambanis

    (Department of Political Science, University of Pennsylvania)

  • Stergios Skaperdas

    () (Department of Economics, University of California-Irvine University)

  • William Wohlforth

    (Department of Government, Dartmouth College University)


Scholarship on civil wars has focused on domestic causes, but recent research suggests that such causes are actually contingent on systemic conditions. We demonstrate this interaction concerning polarization. We provide statistical evidence for the importance of external intervention in conflict escalation. We then construct models in which external intervention is the catalyst for civil war in combination with other factors, focusing on ethnic or social identitification. In our model, local actors with a foreign patron are emboldened and pursue their objectives violently. Without the specter of intervention, polarization is not often suffcient to induce war. The model qualifies important empirical results that have established a direct, linear relationship between polarization and civil war and shows how it is possible to have war without asymmetric information or credible commitment problems. We present case examples consistent with our theoretical claim. The model serves as a bridge between international relations and comparative political-economy approaches to internal armed conflict.

Suggested Citation

  • Nicholas Sambanis & Stergios Skaperdas & William Wohlforth, 2017. "External Intervention, Identity, and Civil War," Working Papers 161705, University of California-Irvine, Department of Economics.
  • Handle: RePEc:irv:wpaper:161705

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    References listed on IDEAS

    1. Salehyan, Idean & Gleditsch, Kristian Skrede & Cunningham, David E., 2011. "Explaining External Support for Insurgent Groups," International Organization, Cambridge University Press, vol. 65(04), pages 709-744, October.
    2. Grieco, Joseph M., 1988. "Anarchy and the limits of cooperation: a realist critique of the newest liberal institutionalism," International Organization, Cambridge University Press, vol. 42(03), pages 485-507, June.
    3. Amegashie, J. Atsu & Kutsoati, Edward, 2007. "(Non)intervention in intra-state conflicts," European Journal of Political Economy, Elsevier, vol. 23(3), pages 754-767, September.
    4. Zhukov, Yuri M., 2016. "Trading hard hats for combat helmets: The economics of rebellion in eastern Ukraine," Journal of Comparative Economics, Elsevier, vol. 44(1), pages 1-15.
    5. David E. Cunningham, 2010. "Blocking resolution: How external states can prolong civil wars," Journal of Peace Research, Peace Research Institute Oslo, vol. 47(2), pages 115-127, March.
    6. Cetinyan, Rupen, 2002. "Ethnic Bargaining in the Shadow of Third-Party Intervention," International Organization, Cambridge University Press, vol. 56(03), pages 645-677, June.
    7. J. Atsu Amegashie, 2014. "Asymmetric information and third-party intervention in civil wars," Defence and Peace Economics, Taylor & Francis Journals, vol. 25(4), pages 381-400, August.
    8. repec:cup:apsrev:v:85:y:1991:i:03:p:701-726_17 is not listed on IDEAS
    9. Fearon, James D, 2003. "Ethnic and Cultural Diversity by Country," Journal of Economic Growth, Springer, vol. 8(2), pages 195-222, June.
    10. Chang, Yang-Ming & Potter, Joel & Sanders, Shane, 2007. "War and peace: Third-party intervention in conflict," European Journal of Political Economy, Elsevier, vol. 23(4), pages 954-974, December.
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