Over half the world lives under authoritarian regimes. For these people, the opportunity to engage in politics moves outside the state's territory. Mobilising across borders, diasporas emerge to challenge such governments. This book offers an in-depth examination of the internal politics of transnational mobilisation. Studying Rwandan and Zimbabwean exiles, it exposes the power, interests, and unexpected agendas behind mobilisation, revealing the surprising and ambivalent role played by outsiders.