Note 234 — Chapter III · WARFARE ON LAND
Reading edition
Says Vattel, III. § 159: "Mais ce n'est point une loi de la guerre d'épargner en toute rencontre la personne du roi ennemi; et on n'y est obligé que quand on a la facilité de le faire prisonnier." The example of Charles XII. of Sweden (quoted by Vattel), who was intentionally fired at by the defenders of the fortress of Thorn, besieged by him, and who said that the defenders were within their right, ought to settle the point.