siege mentality

Etymology
, from the experience of military defenses of real sieges.

Noun

 * 1) A collective feeling of victimization and defensiveness, in which a group of people believe themselves to be constantly attacked, oppressed, or isolated in the face of the negative intentions of the rest of the world.

Translations

 * Dutch: frontmentaliteit, belegeringsmentaliteit
 * German:
 * Polish: