Autumn 2006 Parameters - External Assistance: Enabler of Insurgent Success by Jeffrey Record.

Victorious insurgencies are exceptional because the strong usually beat the weak. But all power is relative, and if an insurgency has access to external assistance, such assistance can alter the insurgent-government power ratio even to the point where the insurgency becomes the stronger side. This is what happened during the American War of Independence. This is what did not happen during the American Civil War. External assistance made Yorktown possible; its absence condemned the Confederacy to Appomattox. To be sure, external assistance is no guarantee of insurgent success, but there are few if any examples of unassisted insurgent victories against determined and resourceful governments.

Much of the key theoretical literature on the phenomenon of weak victories over the strong discounts or altogether ignores the importance of external assistance. Andrew Mack argues that the best explanation of insurgent success is possession of superior political will and therefore greater readiness to sacrifice; the insurgents win because they wage a total war against an enemy that fights but a limited war. Ivan Arreguin-Toft contends that superior strategy—e.g., protracted irregular warfare against a conventional foe—best explains insurgent victories. Gil Merom believes that chances of insurgent success hinge greatly on government regime type; insurgencies fare much better against democracies than against dictatorships because the former lack the stomach for brutal repression.

These explanations share a common assumption: the key to offsetting the stronger side’s material superiority lies in the weaker side’s possession of superiority in such intangibles as political will and strategy. The United States was defeated in Indochina because the Vietnamese Communists displayed a far greater willingness to fight and die5 and pursued a strategy that simultaneously limited their exposure to US military strengths (firepower, air mobility) and exploited American political vulnerabilities (the electorate’s aversion to indecisive, protracted wars for limited objectives)...