Having good foundations for your world doesn’t just mean showing how it works and runs, important though that is, but good reasons behind their policies will make your world and stories that much more convincing. You don’t want anything to sound an odd note, anything that might interrrupt your reader’s enjoyment of your work and think “Nah! Would never work!”.
Could your world’s attitudes change (for worse or better)? Say your world is anti any kind of interaction with other species but changes it mind later as it realises it could trade (for example) with this other species for things it itself is short of, who would take on an ambassadorial role? What mistakes would your world make (potential for both comedy and tragic misunderstandings there)?