28 Introduction for the Libyan cause was high and consistent as foreign powers, the international media, and relief agencies intervened on behalf of the revolution. Strong geopolitical support gave activists opportunities to broker between parties, represent the revolution to outsiders, and remit their labor, cash, and material aid to the front lines. Support for the Syrian cause, on the other hand, varied between US and British governments. This difference gave Syrian Americans an elevated role to play as brokers and representatives, while Syrians in Britain were largely shut out of policymaking.19 Once geopolitical support for the anti-Assad effort waned across the board by 2014, however, most activists’ roles in policymaking were muted in both host-countries. Finally, geopolitical support for the Yemeni revolution was weak in light of Western powers’ backing of an agreement drawn up by members of the Gulf Cooperation Council to supposedly stabilize Yemen (which backfired spectacularly). As a result, Yemenis in the United States and Britain were invited to meetings, but not incorporated into policymaking. This left them hopeful but frustrated with their inability to do more for their compatriots. 1.7 conclusion By bringing attention to the conditions that shape diaspora mobilization over time, this study adds an important chapter to a growing literature on revolutions and the Arab Spring. While much work focuses on the dynamics of contention that unfold within nations, revolutions are not contained events within national territories. Instead, mass revolts against regimes are fundamentally “transboundary” phenomena, as George Lawson describes (2019), that send shock waves across oceans, galvanize extra-national forces, and mobilize activists across borders (Beck 2014; Bell 1972; Berberian 2019). Diaspora participation in the Arab Spring did not, by itself, determine whether the revolutions would win or lose. But given activists’ roles as the revolutions’ publicists, lobbyists, funders, rescue workers, and fighters, explaining diaspora mobilization is essential for understanding one of the most consequential protest waves in modern history, as well as for explaining how contentious events unfold more generally (Abdelrahman 2011; Adamson 2016; Beaugrand and Geisser 2016; Seddon 2014). This book also fills a significant empirical gap in the study of transnational movements, migration, and ethnic studies. Increasing focus on the experience of Arabs and Muslims in the West has brought notable attention to the ways in which opportunities in the mahjar, or diaspora, have been undermined by marginalization in the receiving-country. Arabs and Middle Eastern Muslims have certainly experienced widespread discrimination across the West for well 19 For more information on Syrian cultural brokerage with mainstream media, see also AndénPapadopoulos and Pantti (2013). https://doi.org/10.1017/9781009272148 Published online by Cambridge University Press