Introduction 5 nation-building projects from afar by channeling cash and matériel to their homelands (Hirt 2014; Hockenos 2003; Lainer-Vos 2013; Ma 1990; Maney 2000). In a world where having a nation-state grants ethnic groups protection (Mann 2005), minority movements among Tibetans, Palestinians, Basques, and Kurds have demanded sovereignty and ethno-religious rights in their homelands (Adamson 2019; Bamyeh 2014; Baser 2015; J. Hess 2009). Expatriates with axes to grind, such as anti-communist Cubans and Iraqis opposing Saddam Hussein, have also forged powerful lobbies to challenge home-country governments and shape host-country foreign policy (Ambrosio 2002; Mearsheimer and Walt 2007; T. Smith 2000; Vertovec 2005). In these cases and many others, exiles and diaspora movements have become what Yossi Shain (2005[1989]: xv) describes as “some of the most prominent harbingers of regime change” in the world (see also Field 1971). As authoritarianism resurges across the globe today and in the foreseeable future (Repucci 2020), diaspora movements will undoubtedly continue to play a central role in an increasingly urgent fight against dictatorships. But although they have played a notable role in fomenting change in their homelands for centuries, surprisingly little attention has been paid to explaining their interventions. To fill this gap, I address two central questions: When do diaspora movements emerge to contest authoritarianism in their places of origin? How, and under what conditions, do activists fuel rebellions therein? By systematically investigating how revolutions ricocheted from Libya, Syria, and Yemen to the United States and Great Britain, this book provides interesting new answers. The central contribution of The Arab Spring Abroad is the provision of a set of conditions explaining when, how, and the extent to which diasporas wield voice after exit against authoritarian regimes. In so doing, the book demonstrates that exit neither undermines voice, as Hirschman (1970) suggests, nor does it necessarily foster voice, as historical examples of exile mobilization illustrate. Instead, I argue that while some exiles use exit as an opportunity for voice, diaspora members’ ties to an authoritarian home-country are more likely to suppress voice after exit within the wider anti-regime community for at least one of two reasons. The first is that home-country regimes may actively repress voice in the diaspora using violence and threats. When they do, non-exiles are likely to remain silent in order to protect themselves and their relatives in the homecountry. The second reason is that home-country ties can entangle diaspora members in divisive, partisan conflicts rooted in the home-country. When these home-country rifts travel abroad through members’ transnational ties, they can factionalize regime opponents and make anti-regime solidarity practically impossible. I find that these two transnational forces – what I term transnational repression and conflict transmission, respectively – largely deterred anti-regime diaspora members from Libya, Syria, and Yemen from coming out and coming together against authoritarianism before the revolutions in 2011. https://doi.org/10.1017/9781009272148 Published online by Cambridge University Press