The survey of 15-year-old students in EU countries shows that they strongly support peace and collaboration, but also hold strong nationalistic views that prioritize their own country's interests, even if it means using military force. This nationalistic mindset is influenced by past ideologies and creates fear of losing national culture due to European integration. This study suggests that current education systems in EU countries need to address how outdated nationalistic ideas contribute to inequality and conflict within and between nations. The social knowledge taught in schools reinforces traditional power dynamics among European groups and needs to be updated.