"A national redoubt or national fortress is a general term for an area to which the (remnant) forces of a nation can be withdrawn if the main battle has been lost\u2014or even beforehand if defeat is considered inevitable. Typically a region is chosen with a geography favouring defence, such as a mountainous area or a peninsula, in order to function as a final hold-out to preserve national independence and host an effective resistance movement for the duration of the conflict."@en . .