Although deceit is detestable in all other things, yet in the conduct of war it is laudable and honorable; and a commander who vanquishes an enemy by stratagem is equally praised with one who gains victory by force.
The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.