This article examines how Karen-nationalism is reconstructed and reinforced in a diaspora space beyond the nation-state, focusing on Karen communities along the Thai-Myanmar border. Existing studies of nationalism in Southeast Asia have largely emphasized postcolonial nation-building processes or conflicts between central governments and ethnic minorities. Such approaches, however, tend to overlook the everyday and institutional mechanisms through which nationalism is produced and sustained among displaced populations living outside their presumed national territory. Drawing on ethnographic research conducted in Karen refugee schools and surrounding village communities in Thailand, this study analyzes how language and history education, ethnic hero narratives, and everyday practices collectively shape an imagined community of “We, the Karen.” Particular attention is paid to the shared structural conditions of legal insecurity, economic vulnerability, and social discrimination that characterize the Karen diaspora. Under these conditions, education and everyday practices do not merely transmit ethnic identity but transform Karen nationalism into a social and emotional resource that provides stability, continuity, and collective meaning in precarious lives.