This chapter discusses theory-building and establishes the fact that reliance on a specific set of resistance tactics, violent or nonviolent, helps to determine campaign success. Nonviolent resistance mobilizes a greater number of diverse participants than violent campaigns and increased participation helps nonviolent resistance to fulfil the desired objectives. The chapter also explains physical barriers to participation, informational difficulties, moral barriers, commitment problems, coercion, loyalty shifts, new interests and backfire, external support, tactical diversity and innovation, and evasion and resilience. The disruptive effects of violent and nonviolent campaigns result in significant political, economic, and military costs for an opponent. The chapter concludes with some examples, which prove that sometimes an armed revolution succeeds.