Virtually all rebel groups fight to either overthrow the central government (center-seekers) or to separate. This dissertation presents three papers examining how these differing goals affect the likelihood and consequences of rebels receiving foreign support. The first paper hypothesizes that center-seekers are most likely to be supported by states that are militarily stronger than their home government, and that separatists are most likely to be supported by states that are militarily competitive with their home government. Center-seekers must fight intense wars against stronger opponents to achieve their goals. Therefore, I argue that only militarily strong states have reasonable chances of using support to center-seekers to accomplish their ultimate sponsorship objectives. Unlike center-seekers, separatists can accomplish their goals by fighting lower intensity wars. Consequently, support only enables separatists to inflict modest additional damage. However, potential supporters that are militarily competitive with separatists’ home governments can benefit by providing long-term support. Long-term support can provide these supporters with coercive military advantages over initially equal competitors. Statistical analysis supports the first paper’s hypotheses.

The second paper analyzes how rebels’ goals influence their chances of receiving either high intensity types of support (troops), or solely low intensity support (uniforms). I argue that center-seekers’ are most likely to receive high intensity support from states that are militarily stronger than their home government. I also contend that separatists’ are most likely to receive low intensity support from states that are militarily competitive with their home government. Empirical results support these arguments. 

Finally, the third paper examines when rebel support prolongs civil war. I argue that support lengthens center-seeking wars when the rebels receive high intensity support from states that are militarily stronger than their home government. I also contend that support prolongs separatist wars when the rebels receive low intensity support from states that are militarily competitive with their home government. Statistical analysis supports these arguments. This dissertation demonstrates that rebels’ goals influence 1) what types of states support them, 2) what types of support they receive, and 3) how different types of rebel support impact civil war duration.