the defended locality be fortified or not, since an unfortified place can be defended.[298] And it must be mentioned that nothing prevents a belligerent who has taken possession of an undefended fortified place from destroying the fortifications by bombardment as well as by other means. [Footnote 295: The assertion of some writers--see, for instance, Pillet, pp. 104-107, and Mérignhac, p. 173--that bombardment is lawful only after an unsuccessful attempt of the besiegers to starve the besieged into surrender is not based upon a recognised rule of the Law of Nations.] [Footnote 296: The words _by any means whatever_ were inserted by the Second Peace Conference in order to make it quite clear that the article is likewise to refer to bombardment from air-vessels.] [Footnote 297: See, for instance, Lueder in Holtzendorff, IV. p. 451.] [Footnote 298: See Holls, _The Peace Conference at the Hague_ (1900), p. 152.] [Sidenote: Assault, how carried out.] § 156. No special rules of International Law exist with regard to the mode of carrying out an assault. Therefore, only the general rules respecting offence and defence find application. It is in especial not[299] necessary to give notice of an impending assault to the authorities of the respective locality, or to request them to surrender before an assault is made. That an assault may or may not be preceded or accompanied by a bombardment, need hardly be mentioned, nor that by article 28 of the Hague Regulations pillage of towns taken by assault is now expressly prohibited. [Footnote 299: This becomes indirectly apparent from article 26 of the Hague Regulations.] [Sidenote: Siege, how carried out.] § 157. With regard to the mode of carrying out siege without bombardment no special rules of International Law exist, and here too only the general rules respecting offence and defence find application. Therefore, an armed force besieging a town may, for instance, cut off the river which supplies drinking water to the besieged, but must not poison[300] such river. And it must be specially observed that no rule of law exists which obliges a besieging force to allow all non-combatants, or only women, children, the aged, the sick and wounded, or subjects of neutral Powers, to leave the besieged locality unmolested. Although such permission[301] is sometimes granted, it is in most cases refused, because the fact that non-combatants are besieged together with the combatants, and that they have to endure the same hardships, may, and very often does, exercise pressure upon the authorities to surrender. Further, should the commander of a besieged place expel the non-combatants in order to lessen the number of those who consume his store of provisions, the besieging force need not allow them to pass through its lines, but may drive them back.[302] [Footnote 300: See above, § 110.]