This chapter focuses on concepts and theories illustrated by empirical evidence from different parts of the globe and briefly discusses the concept of 'diaspora', specifically 'conflict-generated diaspora'. It also looks into the concept of 'diaspora mobilization', its operationalizations, and its relationship to 'conflict spiral' and 'contested sovereignty'. Politically relevant foreign policy factors have also been identified to cause diasporas to amplify or reduce conflicts. Established scholarship on ethnic lobbying in foreign policy has been more interested in capturing specifics about how policy lobbying takes place through state institutions, party systems and trade unions. Several scholars have shown the detrimental effects on diaspora mobilizations of critical events stemming from the country of origin, where events associated with violence play an important role. The chapter also discusses the emergence of new theoretical streams to deepen the existing research agenda on diasporas and transitional justice, and on weak and fragile states.