Previous studies have explored two scenarios wherein diaspora members fight for their ancestral homeland: (1) in response to immediate threats, and (2) when the homeland’s conscription laws mandate enlistment. This study investigates diaspora military service (DMS) in Israel, where DMS occurs voluntarily outside of acute crises or compulsory conscription requirements. Utilizing survey and interview data from over 1100 diaspora soldiers, it compares enlistment motivations across three diaspora groups with varied ties to Israel and Judaism: North Americans, Israeli Americans, and individuals from the Former Soviet Union. The study conceptualizes DMS as a state led effort to cultivate an engaged diaspora and advance Jewish immigration. This framework enables examining DMS, beyond the immediate military context, as a site for identity exploration, cultural assimilation, and contemplating permanent immigration. Despite varied emphases, results show that DMS occurs in a migratory context as soldiers from all groups recognize service as essential for immigration, integration, and acceptance in Israel. The study formulates three motivational models that drive transnational military engagement across contexts: the “ideological model” among conviction-driven actors; the “mobility model” among those focused on upward mobility; and the “reconnection model” for cementing national belonging and avoid stigma.