§ 242. Yet legitimate warfare is, on the whole at any rate, secured through several means recognised by International Law. These means of securing legitimate warfare may be divided into three classes. The first class comprises measures of self-help:--reprisals; punishment of war crimes committed by enemy soldiers and other enemy subjects; the taking of hostages. The second class comprises:--complaints lodged with the enemy; complaints lodged with neutral States; good offices, mediation, and intervention on the part of neutral States. And there is, thirdly, the fact that, according to article 3 of Convention IV. of the Second Peace Conference, belligerents are responsible for all acts committed by persons forming part of their forces, and are liable to make compensation, if the case demands it, for any violation of the Hague Regulations. These means, as I have said, do on the whole secure the legitimacy of warfare, because it is to the interest of either belligerent to prevent the enemy from getting a justifiable opportunity of making use of them. On the other hand, isolated illegitimate acts of individual enemy soldiers will always occur; but they will in many cases meet with punishment either by one party to the war or the other. As regards hostile acts of private enemy individuals not belonging to the armed forces, belligerents have a right[467] to consider and punish them severely as acts of illegitimate warfare. [Footnote 467: See below, § 254.] II COMPLAINTS, GOOD OFFICES AND MEDIATION, INTERVENTION _Land Warfare_, §§ 439-440. [Sidenote: Complaints lodged with the Enemy.] § 243. Commanders of forces engaged in hostilities frequently lodge complaints with each other regarding single acts of illegitimate warfare committed by members of their forces, such as abuses of the flag of truce, violations of such flag or of the Geneva Convention, and the like. The complaint is sent to the enemy under the protection of a flag of truce, and the interest which every commander takes in the legitimate behaviour of his troops will always make him attend to complaints and punish the offenders, provided the complaints concerned are found to be justified. Very often, however, it is impossible to verify the statements in the complaint, and then certain assertions by one party, and their denial by the other, face each other without there being any way of solving the difficulty. It also often happens during war that the belligerent Governments lodge with each other mutual complaints of illegitimate acts and omissions. Since diplomatic intercourse is broken off during war, such complaints are either sent to the enemy under the protection of a flag of truce or through a neutral[468] State which lends its good offices. But here too indignant assertion and emphatic denial frequently face each other without there being a way of solving the conflict.