The concept of national identity in the nation-state is influenced by ethno-cultural identity. However, the decline in understanding and awareness among the younger generation in Indonesia has led to a national identity crisis, especially in the border areas. This research becomes a pioneer study investigating the forms and teachers' involvement in strengthening students' national identities at the border areas. The ethnographic approach reveals the depth of teachers' involvement, including students and school communities on the Indonesia-Malaysia border. This study shows that teachers' involvement is mainly through cultural festival activities, in which ethno-cultural identities that contain knowledge of ethnic groups in Indonesia are introduced. The teacher's success brings psychological changes shown in students' awareness and behaviour. This study provides insights and solutions that can be used to reduce the impact of the crisis and reflect views related to national identity. As input, ethno-cultural identity is paramount to strengthen the concept of national identity in the nation-state, especially for the younger generation.