None of these methods of attack can long be persisted in and the assailant, if unsuccessful, must either strike his camp and seek victory in some other direction, as Scipio did when he invaded Africa and, after failing in the attempt to storm Utica, withdrew from his attack on that town and turned his strength against the Carthaginian army in the field; or else recourse must be had to regular siege, as by the Romans at Veii, Capua, Carthage, Jerusalem, and divers other cities which they reduced in this way.

The capture of towns by stratagem combined with force is effected, as by the Romans at Palaeopolis, through a secret understanding with some within the walls.  Many attempts of this sort have been made, both by the Romans and by others, but few successfully, because the least hindrance disarranges the plan of action, and because such hindrances are very likely to occur.  For either the plot is discovered before it can be carried out, as it readily may, whether from treachery on the part of those to whom it has been communicated, or from the difficulties which attend its inception, the preliminary arrangements having to be made with the enemy and with persons with whom it is not permitted, save under some pretext or other, to hold intercourse; or if it be not discovered while it is being contrived, a thousand difficulties will still be met with in its execution.  For if you arrive either before or after the appointed time, all is ruined.  The faintest sound, as of the cackling of the geese in the Capitol, the least departure from some ordinary routine, the most trifling mistake or error, mars the whole enterprise.  Add to which, the darkness of night lends further terror to the perils of such undertakings; while the great majority of those engaged in them, having no knowledge of the district or places into which they are brought, are bewildered and disconcerted by the least mishap, and put to flight by every imaginary danger.  In secret nocturnal enterprises of this sort, no man was ever more successful than Aratus of Sicyon, although in any encounter by day there never was a more arrant coward.  This we must suppose due rather to some special and occult quality inherent in the man, than to success being naturally to be looked for in the like attempts.  Such enterprises, accordingly, are often planned, but few are put into execution, and fewer still with success.

When cities are acquired by surrender, the surrender is either voluntary or under compulsion; voluntary, when the citizens appeal to you for protection against some threatened danger from without, as Capua submitted to the Romans; or where they are moved by a desire to be better governed, and are attracted by the good government which he to whom they surrender is seen exercising over others who have placed themselves in his hands; as was the case with the Rhodians, the Massilians, and others who for like causes gave themselves up to the Roman people.  Compulsory surrenders take place, either as the result of a protracted siege, like those we have spoken of above; or from the country being continually wasted by incursions, forays, and similar severities, to escape which a city makes its submission.