The growing interest in banal expressions of nationalism in everyday life has left the capacity of national identities to cause irregular attitudinal and behavioural reactions to changing circumstances undertheorized. To fill this gap, this article asks when, how, and why national identities have strong impact on public attitudes about events. The article introduces a theoretical framework, which integrates elements from humanistic philosophy, sociology of nationalism, political psychology, and sociology of emotions. National identity protects against existential threats but is precarious because the nation is a phantasmal object of identification whose 'existence' depends on contested narratives. Therefore, events that seem to threaten or promise to alter the perceived core elements of the nation (i.e., 'nation-disrupting events') evoke strong emotions, which motivate attitudinal shifts. Which affective reaction individuals experience depends on the meaning they attribute (spontaneously or in response to elite cues) to events vis-à-vis competing idealizations of the nation.