The purpose of this thesis is to answer the following set of interrelated research questions: do diasporas influence the foreign policy agendas of their host countries regarding their home countries? If so, when do they do it and how do
they do it? In this thesis, I develop a primary explanation and an alternative explanation to test against the evidence I find in my case studies to determine which explanation is the more compelling explanation for the research questions
posed. My primary explanation is that host country foreign policymakers are likely to place a diaspora’s home country policy issue onto the host country foreign policy agenda as a result of a diaspora’s electoral influence. My
alternative explanation is that host country foreign policymakers are likely to place a diaspora’s home country policy issue onto the host country’s foreign policy agenda if the diaspora effectively frames the issue in ways that engage and appeal to policymakers. As case studies, I focus on the Sri Lankan Tamil diasporas in Britain and in Canada, and their respective roles in influencing the foreign policy agendas of Britain and Canada regarding the Sri Lankan civil war. After testing the explanations against the evidence in the case studies, I determine that the more compelling explanation is that diasporas influence the foreign policy
agendas of their host countries regarding their home countries when they effectively frame the issues in ways that engage and appeal to policymakers.