In modern regular wars of the Europeans, and their descendants in other portions of the globe, protection of the inoffensive citizen of the hostile country is the rule; privation and disturbance of private relations are the exceptions.
26
Commanding generals may cause the magistrates and civil officers of the hostile country to take the oath of temporary allegiance or an oath of fidelity to their own victorious government or rulers, and they may expel every one who declines to do so. But whether they do so or not, the people and their civil officers owe strict obedience to them as long as they hold sway over the district or country, at the peril of their lives.
27
The law of war can no more wholly dispense with retaliation than can the law of nations, of which it is a branch. Yet civilized nations acknowledge retaliation as the sternest feature of war. A reckless enemy often leaves to his opponent no other means of securing himself against the repetition of barbarous outrage.
28
Retaliation will, therefore, never be resorted to as a measure of mere revenge, but only as a means of protective retribution, and moreover, cautiously and unavoidably; that is to say, retaliation shall only be resorted to after careful inquiry into the real occurrence, and the character of the misdeeds that may demand retribution.
Unjust or inconsiderate retaliation removes the belligerents farther and farther from the mitigating rules of regular war, and by rapid steps leads them nearer to the internecine wars of savages.
29
Modern times are distinguished from earlier ages by the existence, at one and the same time, of many nations and great governments related to one another in close intercourse.