"This thesis examines a largely unexplored area of deterrence theory - unconventional deterrence. Unconventional deterrence is defined herein as 'persuading the opponent not to attack, via threats of unconventional warfare, such as guerrilla resistance and terrorism.' It treats terrorism as a punishment strategy, through which the one deterring threatens to punish the aggressors population. Guerrilla warfare is a denial strategy, through which the one deterring threatens to protract a war and deny the aggressor his political objectives. This study questions the underlying hypothesis of deterrence theory which says that the balance of the opponents military capabilities is the basic determinant of successful deterrence. Rather, the hypothesis here is that the deterrer may deter the aggressor from attacking by adopting a strategy that makes the aggressors military superiority irrelevant. The present thesis focuses primarily on relatively weak states. Unconventional deterrence is explored as a means for a weaker state to deter a considerably stronger opponent. This thesis discusses the requirements for successful deterrence, and the peculiarities of unconventional deterrence. As well, the dynamics of small wars are explored in order to unfold a paradoxical phenomenon: the possibility of an underdogs victory in war. Two case studies: (1) the Vietnam War of 1964-73 and (2) the Afghanistan War of 1979-89 " are explored as examples of the weak denying the strong their objectives."