What makes individuals willing to defend their (adopted) homeland as their own? This is an essential question for all diverse societies. We turn to the case of Estonia, which inherited a sizable Russian-speaking population after the fall of the Soviet Union. Using recent polling data, we test demographic and attitudinal predictors of defense willingness among the first generation of males that have been raised in the republic since the restoration of independence. The results enable us to unpack differences between Estonian-speakers and Russian-speakers, as well as disagreements among the latter, which shed light on the state of social cohesion in Estonia’s national fabric.