insularity

There are proven ways to win the loyalty of tough, strong, ferocious men: play on the certain knowledge of their superiority, the mystique of secret covenant, the esprit of shared suffering.

Travel was a species of warfare.

... Mr Jellyband was indeed a typical rural John Bull of those days --- the days when our prejudiced insularity was at its height, when to an Englishman, be he lord, yeoman, or peasant, the whole of the continent of Europe was a den of immorality and the rest of the world an unexploited land of savages and cannibals.

The limitation prompting folly " was an attitude of superiority so dense as to be impenetrable.